How to get the ability to publish applications for iOS?

Question

Apple Developer Program

Before that, I only made applications for android, correct me if something is wrong.

First, I need the customer to register at https://developer.apple.com/programs/enroll/

After, as I understand it, I need him to send me an invitation to the team? How to do it? Can I send detailed instructions to the customer?

Also, what else do I need to do?