Can you please try again. I just accessed the link. You can try again: https://microsoftlearning.github.io/DP-900T00A-Azure-Data-Fundamentals/Instructions/Labs/dp900-03-cosmos-lab.html
If it does not still work, I would recommend you try again from a different browser or and incognito tab
You can mark it 'Accept Answer' and 'Upvote' if this helped you
Regards,
Abiola