How to Secure an alternate host in Pro Plan?

How do I add/secure a person as an alternate host in Pro Plan - - if it can be done?

What are the specific steps to do so.

Do I have to redo this for every Zoom meeting I run, even if the same person is tha laternate host?

Is there a fee for such [and is it a one-time fee or must it be paid every time I run a Zoom meeting]?