2020 f150 how can I watch youtube or video in truck can I use forscan? I have an android phone

 

It's not an option. You can bluetooth your phone to it to use as audio but no video.

 

there are options to add camera sources, which includes an hdmi input. only way I could see doing it. can't do it from phone either directly or using carplay/anroid auto

 

You actually can using apple carplay. Not sure about android auto. To use youtube using apple carplay, you would have to jailbrake your iphone. then purchase an app called CarBridge Lite. If you look at the pic below, its the app on the bottom left.