Play sound/video after locking screen lgv20

[AC Question]

Up until recently I was able to play YouTube videos from chrome after locking my screen. I also downloaded the YouTube music app from the play store and was able to listen to that after locking my screen. A few days ago a notification popped up that asked if I wanted to continue to allow videos or sound to play on screen lock (forget exact wording of message) and without thinking I clicked no. Now I cannot find the settings to enable this again. Does anyone have any ideas?