Hi,
Based on the error you are seeing, it seems you didn't enter the correct name for your key vault. You entered "devops-rg" which appears to be the name of a resource group.
Please browse to your key vault in the Azure portal and verify that you are using the correct name. Once you have double-checked the name please try the command again.
Please click Accept Answer and upvote if the above was helpful. If something is unclear or you still need assistance add a comment below.
Thanks.
-TP