registration form api validation

I have a wordpress website where i have build a registration form using Gravity forms plugin. I have used Javascript api to transfer all the details of registration form to another dashboard software system. I have a validation problems eg., if the form is submitted from the front end and due to any reason the form is not submitted or shows any validation error in the backend api dashboard system , then the form should not be submitted from the front end as well. I am searching for freelancer who has knowledge on this validations and skills like Wordpress, Gravity form plugin and javascript api.