How to link custom form to subscriptions and online course enrollments?

Question:
How to link custom form to subscriptions and online course enrollments?

Product:
Wix Studio Editor.

What are you trying to achieve:
I want to get the details like phone number, city, state of the students who enroll to my courses online.

What have you already tried:
I tried booking form but looks it’s different than what I am looking.

Additional information: