I am in the Xbox app and can not change my Xbox profile pic to a custom

You have to use the console or you can use the Console Companion app on PC to do so.

I have a custom pic 1 download the xbox app take a photo or download the photo 2 go to profile change add custom picture

I'm having the same issue also I cant change my profile pic to a custom picture in xbox app everything ****ight now because of quarantine

Do you mean a custom profile pic? If so, the PC app has never been updated to work with that. You can only change it on a console or the mobile Xbox app.

I recommend that you sign into your Microsoft account on the Xbox console, use Profile & system and open My profile.

Use customize profile then, use change gamer-pic. Open Upload a custom image, then select the image.

Personally I do not use a custom image as a gamer-pic. I have no images saved on my Xbox console as files, to upload as a custom gamer-pic.