Hi Martin Ogun,
Thank you for reaching out to Microsoft Q & A forum.
We appreciate your patience. We have notified our internal team of the issue and suggest you to follow this temporary workaround as suggested by TP:
To work around the issue, first Activating the sandbox (solving puzzles, reviewing/accept permissions, etc.) and then once you see the sign-in box appear on the right open a new browser tab. In this new tab, browse to https://ms.portal.azure.com/#cloudshell/ If your existing sandbox hasn't expired you can use that instead of activating a new one.
When prompted, click Bash

Next choose No storage account required, for Subscription select Concierge Subscription, and click Apply.

After several seconds delay while a cloud shell is requested and connected to, you should see $ prompt. At this point you can complete the exercises instructions, copy/paste code from exercise tab to cloud shell tab as needed, etc.
If you have found the answer provided to be helpful, please click on the "Accept answer/Upvote" button so that it is useful for other members in the Microsoft Q&A community.