Thank you, Sidharth! It worked.
As feedback, one thing that would’ve helped as I searched the docs would’ve been if this were documented in the API reference. I was quite puzzled by the fact that the same Endpoint can return different types of Tokens depending on your parameters to it, and even though I had found that the
audience parameter was required for the /oauth/token endpoint to trigger that behaviour for some Flows, the same parameter needs to be sent for a different endpoint/URL on the Flow I’m using, changing the returned token later on (and this behaviour is not documented in the API reference nor in the link that you sent).
In fact, it seems the link you reference says the
audience parameter is mandatory, but we weren’t using it and things were working well - except, of course, for the Opaque Token we got later on.
Thanks for the help once again!