Can I set the audience to have broadcast permission by default?

In Samba Live, the ability to grant broadcast permission to the audience is set at a "per account" level as opposed to via API. This can be done by enabling the Allow Free Publish permission for Audience.

audience

Sessions created within that account will then be pre-configured to grant all audience members broadcast permission. If you would like to have different sets of permissions for different rooms, you would need multiple Samba Live accounts.