As an art teacher, I always found kindergarten to be a tough grade to write art sub plans for. Thinking up lessons that would be simple enough for any random sub to teach took a lot of planning. Sometimes it took a lot of prep too.
After I retired, and art subbed for a while, it reinforced my thinking that I better have a lot planned to keep a class of kinder kids, engaged. I don't mind singing and dancing and doing a lot of movement activities. Little kids are usually up for as much of that as you can provide. After as much of this as I could do and keep them interested, I would do a super simple art lesson. No cutting. No gluing. No paint. And I would try to find lessons that were "no fail."
I do, by the way, have a blog with videos I have previewed. Art Room Videos I don't tend to it much anymore, but there are a lot of good videos in there. Some are great artsy ones and some are just pure entertainment for crowd control.
I would suggest that you have sub ideas on hand for kinder lessons. Those were always the hardest to plan for me. You might look around at this blog and save some ideas. I will go back and tag the ones "kindergarten" that seem appropriate. Print some things out. Go check out some ideas on TpT. I have a shop but there are plenty of others too.
Good luck and take care!