Hi Jack,
I am guessing that you signed up for an Azure Free (with $200 USD credits). These credits expire after 30 days of the trial.
You need to switch to pay-as-you-go:
Change your Azure subscription to a different offer
https://learn.microsoft.com/en-us/azure/cost-management-billing/manage/switch-azure-offer
If you have any billing questions, I'd recommend creating a ticket:
https://azure.microsoft.com/en-ca/support/create-ticket
If this is helpful please accept as answer or upvote.
Best regards,
Dillon Silzer, Director | Cloudaen.com | Cloudaen Computing Solutions