I want my google play music to that app.
Is there a way you can do that on a note 3?
Posted via Android Central App
Honestly, I don't believe that there is...at least not an easy way without a computer anyway. Google Play Music will allow you to "cache" (download) songs for offline use, but they aren't usually visible to other music players.
The bottom line is that you would need to get the actual MP3 tracks stored on your device somehow. Obviously the easiest way would be to use a computer to transfer the files or put them on the SD card. That's a limitation of the app you're trying to use...it's meant for playing
local music files, whereas the Google Play Music app can play both your online library AND local files.
I'm sure you have your reasons why you want to do this, but my advice would be to use the Google Music app instead.