Viewing Female Non Mehrams in Videos Allowed?

Do i have to lower gaze if like there is a girl in video with or without hijab? I had this doubt I usually watch youtube for Studies these days and a few teachers(females) come on ads i just redirect my focus to skip button immidiately as an attempt to lower my gaze. and if i am watching some video and there is a girl in it then also do i have to lower my gaze? and what about if i watch some movie i rarely watch movies but what to do in such a situation