Hi @skorphil
Thank you for posting your inquiry regarding the issue that you are facing.
I would recommend you to visit our documentation related to Configuring Silent Authentication and our documentation about the SPA SDK which provides info about using Rotating Refresh Tokens and getting the Access Token without interaction.
There is also a Knowledge Article about using Refresh Tokens with React.
Additionally, the audience for the access token needs to be your generic Auth0 tenant URL, you will not be able to use your custom domain as audience.
If you have any other questions or still having issues with implementing refresh tokens, please feel free to leave another reply on the post.
Kind Regards,
Nik