I asked the access to check and help you. Without access, it is difficult to help. However, try this.
Please use this JavaScript to
Template Options -> Custom Code -> Custom JavaScript on your English template style. Please follow this article steps. You should have duplicated template styles and using separate template for English language. So, set this code on your English template and check.
jQuery(function($){
$(".sppb-form-control").attr("oninvalid","this.setCustomValidity('Please fill out this field')");
});