I didn't know for sure, so I did a quick search:

>“It's is safest to shut off your vehicle to avoid a fire, static electricity or a check engine light,” says Lauren Fix, an ASE certified technician and sector analyst at The Car Coach. “The fire risk is that the fumes burn, not the liquid. This could lead to an explosion.”

>
>https://www.familyhandyman.com/article/can-i-pump-gas-with-my-car-on/#:~:text=%E2%80%9CIt's%20is%20safest%20to%20shut,could%20lead%20to%20an%20explosion.%E2%80%9D