A movie about friends who spend the night in a cave of a bar for money but they are not alone ?

It’s a movie about a group of friends on holidays who spend a night in a bar.
There is a jar full of money ont the counter and the bartender says it’s a game, you need to put money in the jar to play, and spend the night in the cave, if you do it you win the jar but no one have won it already.
Half of the group go in the cave and the other half continues to drink, they then join them in the cave but they all are hiding and they say that someone is in the cave with them !

I was a kid when I saw that in the 90’s, and my parents sent me to bed before I could finish it..

Thanks a lot if you find it 🙂