Ah, okay @NiceIlagan. Yes, the Zoom Community is made up of volunteers with no access to anything on your account.
Take a look at this Zoom Support article with some details on how to make this change without the hassle of making a support ticket. Assuming that your client can still log in to the Zoom account, one of the techniques listed here should work; you shouldn't need access to the email account for these steps, everything is done in the Zoom account.
If you still need to create a Zoom support ticket, your best option is probably here:
https://support.zoom.us/hc/en-us/requests/new
The "Bolt assistant" also gives you an option to chat online, but I doubt they will change the account ownership in a chat, and I suspect they will make you jump through a number of validation hoops before even doing it via a ticket.