HA as default google assistant speaker

I would like to know if there is any way to set my pi4 (on wich im running HA) to be seen in my google home assistant as a default speaker.

My pi4 is mounted just behind my amplifier, while my home mini is on the over side of the living room, if I could set to automatically send audio to my pi when I ask google to play some music it would be very nice.

For now I’m using a bluetooth antenna but it seems a junky solution.
I have tried the google assistant SDK plug-in, even if it works and I see my device in the google home app i can’t choose it as my default speaker for my home mini.

In this video, don’t know how, they do exactly what I want to do. Im guessing is matter of API or something like that?

Have you find any solution? I have the same need, because my Google home is close to a Bluetooth speaker and I want to set it up as default, but whenever it turns off, GHome reset the default to its own internal speaker.

No, but I think I found the problem. the google assistant sdk doesn’t allow to stream content to the speaker. so i think we have no choice but to buy a used chromcast audio or find some maker who has registred a product that allow that. the option diy it seems impossibile right now due to google kindeness in locking any api.
If someone discovers I’m wrong or know a work around please let me know.

Did google already change this, a few years later?

Because, I have been able to set my HomeAsisstant Media Player as default speaker in the google home app, but when i ask the home speaker to play some music, it plays on the speaker itself instead of the default HomeAsisstant Speaker.

The HomeAssistant speaker is a bose speaker, via the bose soundtouch integration.