Buy Looker Studio Pro licences

I’m trying to buy looker studio pro licenses for a developer to trial.
I’ve tried various email addresses associated with the organisation but am getting the error message:
“Enter a valid email address” - please could anyone point me in the right direction. The email addresses entered is correctly typed, and mine is the owner of the organisation. The developer thinks it maybe because the email is not an email address set to use gmail? Thanks in advance, David

Hi David, you need to use either Google Workspace or Cloud Identity to subscribe to Looker Studio Pro. Can you also double check you’ve set all the right permissions as described in the “Before you begin” section on this page?
https://support.google.com/looker-studio/answer/13715508?hl=en

Hi Sweidenk - I’m very new to this, so it’s probably me, but maybe there’s something odd.

I’ve managed to subscribe to Looker Studio Pro by logging into Looker Studio, choosing Enterprise Admin, “clicking Pro Subscription” and adding the 2 email addresses I wanted.

However initially doing the same thing from within Google Cloud - search for Looker Studio - make sure I’ve got the right organisation/project. Click subscribe. Enter the same email addresses and for both I get “Enter a valid email address”. Also please don’t take offence but that error message makes me think I’ve entered an email address which isn’t properly formed - shouldn’t it say something like - user isn’t in organisation, user doesn’t have X permission etc.