How to connect bluetooth input to Hifiberry using PulseAudio

I connected 2 conventional speakers to a Raspberry Pi 3 using the HiFiBerry AMP2. This works fine with Volumio. Now I want to take it one step further: instead of using Volumio I want to use the Raspberry PI as a speaker for my Echo Dot so that I can use voice-control to play TuneIn radio on that setup. I chose to use Raspberry OS 32-bit Bullseye + PulseAudio v34 and used several blogs and tutorials to get to where I am but I'm stuck in the final step. What works: HiFiBerry AMP2 works well - tested with Volumio I can play a song musing with mplayer My phone can connect to the Pi and shows it c

Question by Axefield on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.