I'm building a backend system in which I'll be querying multiple APIs on the behalf of the user through OAuth (Slack, Hubspot, etc). Note, this is just the backend. Question is, once I have the access and refresh tokens, do I just store them in a DB (encrypted I presume) per user? If yes, then I need to handle the refresh cycles and worry about security.
Are there any services/libraries I can use to handle this for me? I was looking at Auth0, AWS Cognito and Firebase but those seem a bit different as they authenticate the user for me, but I cannot use the tokens for querying resources.