How to integrate a service with auth0, password vault on different customers

Hey auth0 community,

I’ve searched in the forum to find something about integration a password vault with auth0, but couldn’t find a hint to our workflow.

We have a workflow, in which our customers calling a service from us which must be authenticated (via auth0).
The service now must receive credentials from a vault because with those credentials it will call a 3rd party api.

Our thoughts were, that because the token from auth0 to authenticate our service is unique we could match it with a vault entry.

Of course each of our customers have unique credentials from the 3rd party api.

In short:
n-customers calling one service (unqiue auth per customer of course), receiving their unique credentials and call one 3rd party api

Any recommendations or hints how we could/must proceed in setting those things up?
Should we use one organization per customer with setting up our service per organization to have an unique token?
Additionally is there a way to connect auth0 with a password vault (HashiCorp Vault / Azure Key Vault / Doppler etc.) and how can this be done?

Any thoughts about it would be great