@J P Thank you for reaching out to us, As I understand you are trying to create a tenant from pay as you go subscription.
A recent hotfix now restricts tenant creation by requiring paid P1 or greater licenses. If the Entra ID P2 license is a trial license, that is not enough. Customers attempting to create tenants with trial P1+ licenses will also fail in creating tenants. I hope this helps.
Refer to this guide - https://learn.microsoft.com/en-us/entra/fundamentals/get-started-premium sign up for a paid P1 license.
Also review this QnA post for similar requirement - https://learn.microsoft.com/en-us/answers/questions/1435292/unable-to-create-new-entra-id-tenant-with-payg-acc
Let me know if you have any further questions, feel free to post back.
Please remember to "Accept Answer" if answer helped, so that others in the community facing similar issues can easily find the solution.