Sony 1000 Mx3 amd Bluetooth

Hi everyone.
I just received a Raspberry Pi4 and am an absolute newbie. :blush:
At the moment I have installed Volumio in it, and I have configured with little problems the access to my NAS Synology and my Spotify account. (It took me a while to define the correct path).
I plan to buy an Alo Boss DAC when they have stock, and an iPower power supply, but after listening to the music directly from the RPI with a Shenheiser headphones through the 3.5 jack, I’m surprised at how good it sounds already.
I have Sony 1000Xm3 bluetooth headphones and I don’t know how I can make them sound.
Can anybody help me?

Thank you very much in advance.

I’m reading the whole geeks-r-us thread about a plugin to connect bluetooth, but the date is 2017 and RPI3.
I have also visited your blog, but it is too high a level for my knowledge.

I hope someone helps me.

Thank you.