How To use auth0 to "just" set up a minimal api to an external api requiring oAuth2 from my side?

How can I use oAuth0 in an asp net core minimal api backend that needs to do authenticate via oAuth2 to an external (not mine) api? All samples I did see so far, are doing Oidc and none of them just oAuth which is even the name of that whole product

the api is no oidc and the contrib repo to oauth on github does not have this api listed, the ms docs are missing the oauth section completly, only starting at oidc or the azure identity provider, which does not help on the task to get the initial token from that external api.

Can I use the oAuth products for this somehow?
the api of mine should get contacted from my client app via cookies, handle the identity resolving in the end, and do the oauth flow to external apis