Sending a signal over bluetooth

Hello everyone!

I am currently working on a project, where I need to send an audio file (wav) to bluetooth headphones.
I am currently using a raspberry pi with Thonny. I want to have at least 2 bluetooth headphones connected, however, always send the audio signal to just one of them. Which one I want to send it to varies and depends on different signals currently being sent out in my code.
I am able to connect the bluetooth devices and know their mac adress.

I am a beginner with python and cannot figure out how to do this.
Thank you for your help!!

Where exactly are you getting stuck at the moment? For example, if there were only one set of headphones connected, would you be able to solve the problem?

Yes I was able to send the audio to one connected headphone.
However, now I need to send it to upt to 4 different headphones. But not at the same time. I have a trigger that says to which bluetooth headphone the audio should be sent to. This happens almost randomly (both to which headphone it should be sent to and the time intervals between it being sent)

One problem I think I might have found is that I can only send the audio to the default selected device, which is just one of the headphones.