ERPNext Portal Web Views / Web Forms Create a Save button and action


I am working on the customize doctype, and I want to create a Web View, which I did. The question is how do I add a button to save the form? Do we have APIs to get all the data on the webpage?

A reason why I am using the web view is that the Web Form does not have Geolocation. Is there a way to create custom HTML and js on the form?