How to store client credentials?

Question

I am creating a WebAPI (Core/ .Net 6).

When creating the Registration for the app i add some client credentials. I noticed once i have them i cant view one half of the credentials again.

I did a test by making a call to ..{tenant_id}/oauth2/v2.0/token and passing in the client_id and secret (along with other params) i was able to make a successful call.

I feel in future i may not remember to store the client credentials or i may need to pass them over to the same organisation for whatever reason.

Is there a way to tackle this type of scenario? I did read on Azure Key Vault but the demos only showed how it protected VMs or databases.