I have a Samsung Note 8
I use Hi-Fi Cast
-plays music on your phone normally
-includes selections to send your music to other devices (car, modern amp, smart home speaker, Bluetooth speaker...)
-is free
-sometimes there's a screen ad for paying to purchase and you can do that to make the screen ad go away, or just close it
-I just close the ad screen and it's always worked great for me
-I don't use it a lot