Balance the music against your voice
The music should be clearly audible while every word stays easy to understand.
There isn't one correct dB setting for every music file. In my edit the supplied music was already a quieter version, so we used 0 dB clip gain, which means leaving that file's original volume unchanged. Reducing it by another 8 dB made it too quiet.
That's a reference for that one file, not a preset for every podcast. Ask Astra to balance your music against your voice, then listen to the exported preview. Once you approve the balance, save the setting with that exact music file for future episodes.
If the music is missing, ask Astra to check that it is on the timeline, unmuted, and included in the audio export before changing the volume.