Hi Aman,
Please Activate a new sandbox, solve puzzles, review permissions, accept, etc. You may need to wait a few minutes for your existing sandbox to expire since they are valid for 1 hour. Once you see black cloud shell on right, open a new tab and browse to https://shell.azure.com .
You can copy/paste the code blocks from the exercise and execute them in the separate browser tab.
Please note that you need to complete the Unit 3 exercise and then the later Unit 9 exercise in sequence using the same sandbox.
Please click Accept Answer and upvote if the above was helpful.
Thanks.
-TP