Hey! I actually could help answer this one because I use my own PNGtuber getting hit and having them react. That is going to be model specific, and you will need to have a separate piece of art showing your character with a "hit" reaction (Like them scrunching their face). Once you have once, you can use a software like Veadotube to set a new trigger and run a command. Set a command to toggle a throw, to toggle your "hit" character and then back to default model. Only downside with this is that you can only choose one Model to reset back to once you recover from being hit, so you may need to put in some more work.