In our world, we have two systems that the customers use - a web portal and an experience cloud community. We have an Auth Provider setup in our org for users to login to Community and the same authentication service is used in the Web Portal as well.
Currently, we have a custom REST endpoint exposed in SF. The Web Portal invokes those endpoints for data manipulation as Integration User. We want to get away from the integration user and have those transactions performed as them.
Issue:
Can we use the token/code generated during login to Web Portal and pass it to Salesforce to grant access to REST endpoints? What steps do I need to follow? Any reference to documentation will help. Do we make use of the "OAuth-Only Initialization URL" from the Auth Provider settings and pass in the access token to generate a valid session with SF?
https://salesforce.stackexchange.com/questions/15771/authentication-on-api-calls-with-federated-sso
Check this link. This might help out. But honestly a very interesting use case it is
