Chains and Pullup Bar for Tree Branch?

I’m hoping to get a Christmas gift of a pull-up bar for my partner that is an actual bar but we can connect to chains that are looped over the branch of a tree in our backyard. I can’t really seem to find anything like that available online - does anyone have recommendations? I would ask my partner but I want it to be a surprise!

The only things I’ve found online that are somewhat similar are two separate chains with rings on the end, but this isn’t quite what I’m looking for. Any ideas or leads would be hugely appreciated.