Fuel cut-off on, car won't start?

Hello ✌🏻

Yesterday I filled up my car (Fiat 500 2007bj 100ps) (I'm 100% sure that I filled it with petrol) but shortly afterwards my engine started to jerk and finally died. After a few attempts to start it, the speedometer showed "fuel cut-off" and it just turned over when it started but nothing else happened.

I had the car towed and checked again the next day. My suspicion was that the engine was flooded and the cylinder was full of gasoline. The next day, I removed the spark plugs, which were dry, but they didn't look good either. I couldn't test them because the battery was dead.
I put everything together and tried to push the car, but that didn't help either.

Afterwards I took a friend's battery and read the car. Unfortunately I deleted the error codes before I could see them, but the device showed me errors with:

-CAT (catalyst)

-O2s (Oxygen sensor)

-Hrt (oxygen sensor heater)

My guess is that this is the air mass sensor (MAF) but I don't have the money to order at risk.

Maybe there is someone here who knows or has already had the problem

Thank you in advance from me ✌🏻