How to keep factory back up sensors w/ after market head unit?

[apeck5173]

so I am trying to put in a after market head unit in my 2015 since for some reason blue tooth isn't standard.

I used the harness adapter for the factory connection to the new unit. but i noticed i do not have audio for the back up sensors now. Is there something extra I need to do. What wire is providing that sound?

 

[regal81455]

I know with the idatalink stuff there is a seperate speaker that needs to be bought. Unsure about other manufacturer's.

https://www.crutchfield.com/p_794ACCSP1/iDatalink-SP1-Chime-Speaker.html