How to turn off the Backup Camera Alarm

[1GR8DA]

Just brought home a 2018 Expedition Max XL with the Sync not Sync3. It's got the small screen I can't for the life on me figure out hot to turn that thing off. I can pull up the screen but the sound option is greyed out.
Any suggestions would be appreciated.
Thanks!

 

[1GR8DA]

Nevermind. Apparently it's the brown wire.....