Providing document create via API in Adobe Sign

I am looking for a way to generate the document template itself via PI, meaning provide a view where my users upload a file and use GUI to add form fields.

I don't want them to go on adobe page, login and do it from that interface,

All I can find is a an API call where I provide the file and x/y/width/type objects for form fields, meaning I need to implement the setup form field myself?

Isn't there a way to use the setup screen already availabe?

Appreciate your assitance.

Y.