(REQUEST) To continue playing when screen turns off and pausing with earbuds

I would love to listen to Khan academy classes while walking my dog or doing the dishes, but it stops playing when I turn off the screen (to put the phone in my pocket,) so I cant listen* to it while doing other things. I also cant pause/play the video with my earbuds when the screen is off, so if I need to switch my attention, I can't pause it and may lose my place in the class(which can be annoying.)

*Parenthetically, I dont want the screen on while in my pocket; a) because I might by accidentally call someone, b) I might bump into the screen with my leg and skip through the video or pause it...etc.