Hi @BridgeWater,

To access work items via Azure Devops APIs, you need to to add 3 API permissions in app registration - vso.work vso.work_full vso.work_write.

To get the OAuth token you need to pass the below URL in the scope parameter:

https://app.vssps.visualstudio.com/.default

You will get the user access token with this scope.

But if you pass vso.work vso.work_full vso.work_write while calling the auth API, you will get the below same error:

Hope it helps, thanks!