We are running an API that is configured for and secured by Azure AD. This is working for us with an Angular app where users login interactively. Now we have a need for a partner firm to use the API in a system to system way (no user login).
What needs to be configured for their application to get an OAuth token for our API from Azure AD?
I've examined the service to service call flow, but I'm wondering if it's best practice to create an application registration in our tenant for an application we don't own/manage. However this seems to be the fastest way to give them a client ID/Secret in order for them to interact with Azure AD.
Thanks in advance! -Doug