Adding technical account in customer account

Hey community,

I am a web developer and have a customer using Zoom for Webinars (so pays for the service). I am developing an private marketplace app for that customer using the Webinar API. The problem I have is the license. I need to use the customer account to create the app because I don't have a payed Zoom Webinar license account for myself.

Here is my question now: Is there a way to a sort of create a sub account / additional administrator account to the main account of my customer so that I can work independently from them? Their account is secured by a secure code via email and I don't want to ask day by day.

Thank you.