Can you reverse a video layer in Photoshop?

I need to create an animated gif that animates, reverses, then restarts as a loop. I have a set of pngs in a folder on my desktop that make up the animation. I went to Layer > Video Layers > New Video Layer From File. I selected the first png and that loaded all of them as one video layer on the timeline. If you scrub the playhead you can see it animate forward. I haven't found anything that works online to duplicate this video layer, move it to the end of the first one, and reverse the duplicate. There's no frames here, it's one single video layer now. Is it possible? I'm using Photoshop 21.0.1. Thanks for any help.

{Thread renamed by moderator}