How to Set a Default Country on the Vendor Registration Form

declare(strict_types=1);

add_action(

    'wp_enqueue_scripts',

    static function () {

        $registration_page_id = (int) get_option( 'wcv_signup_registration_page_id', 0 );

        if ( 0 === $registration_page_id || ! is_page( $registration_page_id ) ) {

            return;

        }

        $default_country = 'US'; // ISO 3166-1 alpha-2 code (e.g., GB, CA, AU, …)

        wp_enqueue_script( 'wcv-signup' );

        wp_add_inline_script(

            'wcv-signup',

            sprintf(

                "window.addEventListener('load',function(){var el=document.querySelector('#wcv-registration-form select[name=\"country\"]');if(!el||el.value){return;}el.value='%s';el.dispatchEvent(new Event('change',{bubbles:true}));});",

                esc_js( $default_country )

            ),

            'after'

        );

    },

    30

);