CybroAddons/website_restrict_country/views/website_templates.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <!--website_sale.template_header_default inherited template -->
    <template id="template_header_default"
              inherit_id="website_sale.template_header_default">
        <xpath expr="//t[@t-call='website_sale.header_cart_link']"
               position="after">
            <t t-set="countries"
               t-value="request.env['website'].browse(request.website.id).country_ids"/>
            <t t-set="country"
               t-value="request.env['website'].browse(request.website.id).default_country_id"/>
            <div class="country_select_m">
                <t t-call="website_restrict_country.country_selection"/>
            </div>
        </xpath>
    </template>
    <!--Templates for Country Selection menu-->
    <template id="country_selection">
        <t t-if="country">
            <li class="nav-item dropdown o_no_autohide_item js_countrymenu">
                <a href="#" role="button" data-bs-toggle="dropdown"
                   id="a_select"
                   class="dropdown-toggle nav-link fw-bold">
                    <img id="img_code_vat" class="js_img_country_code"
                         t-att-src="country.image_url"
                         width="30" height="20"/>
                </a>
                <div id="country_selection_menu" role="menu"
                     class="dropdown-menu  ">
                    <t t-foreach="countries" t-as="country">
                        <a href="#" class="dropdown-item js_countries"
                           t-att-id="country.code"
                           t-att-data-country_id="country.id"
                           t-att-data-country_code="country.code"
                           t-att-data-country_image_url="country.image_url">
                            <img t-att-data-country-id="country.id"
                                 t-att-src="country.image_url"
                                 width="30" height="20"/>
                            <span t-esc="country.name"/>
                        </a>
                    </t>
                </div>
            </li>
        </t>
    </template>
    <!--website_sale.suggested_products_list inherited template -->
    <template id="cart_summary_inherit_website_country_restriction"
              inherit_id="website_sale.suggested_products_list">
        <xpath expr="//td[hasclass('td-product_name')]" position="inside">
            <t t-set="country_availability"
               t-value="line.product_id.product_tmpl_id.country_availability"/>
            <t t-set="product_select_country"
               t-value="line.product_id.product_tmpl_id.country_selection_ids.mapped('country_id').ids"/>
            <t t-set="current_select_country"
               t-value="request.env['website'].get_current_website().default_country_id.id"/>
            <t t-set="message_cart"
               t-value="request.env['website'].get_current_website().cart_message"/>
            <t t-if="current_select_country not in product_select_country and country_availability == 'selected'">
                <div class="text-warning">
                    <t t-esc="message_cart"/>
                </div>
            </t>
        </xpath>
    </template>
    <!--website_sale.product_buy_now inherited template -->
    <template id="buy_now_restriction" name="Buy Now Restriction"
              inherit_id="website_sale.product_buy_now">
        <xpath expr="//a[contains(@t-attf-class, 'o_we_buy_now')]"
               position="replace">
            <t t-set="current_select_country"
               t-value="request.env['website'].get_current_website().default_country_id.id"/>
            <t t-set="product_select_country"
               t-value="product.country_selection_ids.mapped('country_id').ids"/>
            <t t-if="not product_select_country or current_select_country in product_select_country">
                <a role="button"
                   t-attf-class="btn btn-outline-primary o_we_buy_now ms-1 #{'btn-lg' if ctaSizeBig else ''}"
                   href="#">
                    <i class="fa fa-bolt me-2"/>
                    <span style="font-weight:bold">BUY NOW</span>
                </a>
            </t>
        </xpath>
    </template>

    <!-- website_sale.short_cart_summary inherited template  -->
    <template id="checkout_process_country_restriction"
              name="Checkout Process Restriction"
              inherit_id="website_sale.short_cart_summary">
        <xpath expr="//a[hasclass('d-xl-inline-block')]" position="replace">
            <t t-set="availability"
               t-value="website_sale_order.website_order_line.mapped('product_id.product_tmpl_id.country_availability')"/>
            <t t-set="product_select_country"
               t-value="website_sale_order.website_order_line.product_id.product_tmpl_id.country_selection_ids.mapped('country_id').ids"/>
            <t t-set="current_select_country"
               t-value="request.env['website'].get_current_website().default_country_id.id"/>
            <t t-if="all(country=='all' for country in availability) or current_select_country in product_select_country">
                <a role="button"
                   t-if="website_sale_order and website_sale_order.website_order_line"
                   class="btn btn-secondary float-end d-none d-xl-inline-block"
                   t-attf-href="{{redirect_url}}">
                    <t t-if="redirect_to_sign_in">
                        <span>Sign In</span>
                        <span class="fa fa-sign-in"/>
                    </t>
                    <t t-else="">
                        <span>Proceed to Checkout</span>
                        <span class="fa fa-chevron-right"/>
                    </t>
                </a>
            </t>
        </xpath>
    </template>
    <!-- website_sale.cart inherited template  -->
    <template id="proceed_to_checkout_country_restriction"
              name="Proceed to Checkout Restriction"
              inherit_id="website_sale.cart">
        <xpath expr="//a[hasclass('float-end')]" position="replace">
            <t t-set="availability"
               t-value="website_sale_order.website_order_line.mapped('product_id.product_tmpl_id.country_availability')"/>
            <t t-set="product_select_country"
               t-value="website_sale_order.website_order_line.product_id.product_tmpl_id.country_selection_ids.mapped('country_id').ids"/>
            <t t-set="current_select_country"
               t-value="request.env['website'].get_current_website().default_country_id.id"/>
            <t t-if="all(country=='all' for country in availability) or current_select_country in product_select_country">
                <a class="btn btn-primary float-end"
                   role="button"
                   t-attf-href="{{redirect_url}}">
                    <t t-if="redirect_to_sign_in">
                        <span>Sign In</span>
                        <span class="fa fa-sign-in"/>
                    </t>
                    <t t-else="">
                        <span>Process
                            Checkout
                        </span>
                        <span class="fa fa-chevron-right"/>
                    </t>
                </a>
            </t>
        </xpath>
    </template>
</odoo>