How can I use Linked services in Azure Data Factory to manage an OAuth Web Activity

Question

I have setup a Linked Service in Azure Data Factory to use in a Copy Activity to access Graph APIs, which require use of the OAuth protocol, which works fine. I now want to extend that to use the same Linked Service with a Web Activity. But in tests, it is returning "Empty Token"; Am I missing a (simple) config. option, or am I misunderstanding something?

Earlier, I used explicit Token fetch, which also works fine, but as my queries will - in Production - take longer than the (default) Token TTL, I did not want to have to implement Token refresh, at least not if the Linked Service will handle it for me.

Answer 1

I'm grateful to https://learn.microsoft.com/answers/users/7986441/carlzhao-msft.html for pointing out that I need also to specify, in the Web Services Settings Tab, the Authentication as Managed Identity, with the accompanying Resource as https://graph.microsoft.com/, for my Use Case