Limit Billing Address Block to specific country and state

set_specific_country_state.php

add_filter('give_countries', 'my_custom_give_countries');
function my_custom_give_countries() {
    $countries = array(
        'CA' => esc_html__( 'Canada', 'give' ),
    );
    
	return $countries;
}

<?php

add_action('givewp_donation_form_schema', function($form) {
    $countryField = $form->getNodeByName('country');
    if ($countryField){
        $countryField->defaultValue('CA');
    }
	$province = $form->getNodeByName('state');
	$province->defaultValue('Alberta');
});

add_filter('give_canada_provinces', 'give_custom_provinces');
function give_custom_provinces( $provinces ) {
    $provinces = array(
        'AB' => esc_html__( 'Alberta', 'give' )
    );
    
	return $provinces;
}