I was thinking about buying a fipperzero and wanted to know if i can hack the bus ticket machine and clone the free bus pass
It all depends on the standard used by the tickets and ticket machines.
I would expect the ticket cards to be at least protected by not publicly known keys (if using Mifare protocol at all).
You could try your luck with the Detect reader option and mfkey32, but your mileage will vary.
Another thing is understanding the data format on the card to do anything useful with it.
From my own experience in this topic, I tried to read the public transport cards from two cities.
One uses Mifare with secret keys, but the readers don’t respond to Flipper’s Detect reader. No luck here.
Card from the other city shows up as Unknown ISO tag, so not even Mifare. No luck as well.
But all this depends on what standard is used.
Don’t do this. You will get intro trouble for sure if you or someone else gets cought with changed/false tickets or tickets edited to avid paying … Then you will go to jail-