Hi, I use this: TUNAI Firefly Bluetooth Receiver: World’s Smallest USB Wireless Audio Bluetooth 4.2 Adapter with 3.5mm AUX for Car/Home Stereo Music Streaming; Auto On, No Charging Needed - Car Kit (Black) https://www.amazon.co.uk/dp/B01HXXJPWK/ref=cm_sw_r_cp_tau_Go.1Eb0ZRM15D
Works a treat.
Edit: It looks a bit rough in the pic because I’ve added heat shrink sleeving becuase the white LED was so bright.