Hi @psr11140
I am sorry about the late reply to your inquiry.
Since you want to make calls to the Management API using your own API, you can refer to this community post which had a similar issue. Make sure to enable the Client Credentials grant so that you will be able to receive an access token from the management api to make the requests you are looking for.
From what I notice in the screenshots, you do not appear to be using a custom domain, however if you are looking into doing so, you can refer to this community post regarding the matter.
Related to your question regarding adding extra audience to a token, unfortunately, Auth0 does not support the feature at this time. You can look into alternative approaches regarding this approach. You can always post on our Feedback page regarding implementing this feature.
If you have any extra questions or already solved this issue, feel free to leave a reply or post again on the community page to let us know!
Kind Regards,
Nik