Looks like there is an issue with https://docs.microsoft.com/en-us/learn/modules/create-serverless-logic-with-azure-functions/3-create... I following guide(creating function app on sandbox), but verification always fails, so I cannot finish this module and access further learning materials. Also after few retrials subscription is dropped from sandbox, so I need to wait for another ~3 hours. Tried differend browsers (Edge, FF, Chrome) including incognito modes.
UPD: waiting for some time (15 minutes) after creating your azure functions application and before hitting the button helped in my case, after that time verification succeeded
