leaky-paywall-basic-shipping-adjust-countries.php

<?php

add_filter( 'leaky_paywall_basic_shipping_countries', 'zeen_us_and_canada_only' );

function zeen_us_and_canada_only( $countries ) {

    $new_countries =  array(
		  'US' => 'United States',
		  'CA' => 'Canada'
    );

    return $new_countries;

}