Take a look at where the plant snapped. Did it actually break or did it just crush the stem? Either way its honestly not a big deal and the plant will recover just fine, it's just how you help it is different.
If the stem actually snapped and it is broken open, grab some plastic wrap and tape to set it back in place and bandage it up. the plastic wrap will keep moisture in, seal the wound from infection, and make it easier to remove the tape once healed. It shouldn't take super long time to heal. Maybe 5-7 days. If you don't think its fully healed leave the bandage on longer.
If the stem just wound up getting crushed and isn't snapped open then you don't need to bandage it up, even if the outer skin has cracked a little. This is actually a high-stress training technique used to help train down stubborn stems that don't want to easily bend. even though its is labeled as a high-stress training, it really doesn't phase the plant at all. I was experimenting with a plant a few grows ago where I did tons of super cropping breaking each branch 5-6 times over the course of the grow and then tying them down. Each time o crushed the stems and bent em down, they were back up and starting to recover already the next day within 24 hours. So if this is what happened I wouldn't worry about it.
all in all the plant will recover just fine. Even if that 1 branch broke off completely it wouldn't kill the plant. That one branch would just be lost. Thankfully here it seems like it is still quite attached so you will be just fine.
Good luck with this and I hope for a speedy recovery! if you need any more assistance feel free to dm me!