Hide & refresh WooCommerce checkout after add coupon

Solution:

Your code should be like this

add_filter( 'woocommerce_coupons_enabled', 'woocommerce_coupons_enabled_checkout' );

function woocommerce_coupons_enabled_checkout( $coupons_enabled ) {
  if(is_checkout()){
    global $woocommerce;
    
    if ( ! empty( $woocommerce->cart->get_applied_coupons() ) ) {
        $coupons_enabled = false;
    }
    }
    return $coupons_enabled;
}

Edit: okay you need to check if page is checkout or cart then run the script. I have added condition in code.