If you have to release a tutorial video to open your fuel filler door, and that video includes the one easy piece of user interface to do the thing getting thanos-snapped out of existence, I think you did something wrong.
The cause of my problem was I opened the driver's door before turning off the car. The rental didn't have push-to-start like my personal vehicle, and I don't have "turn and remove key" on the mind when exiting a vehicle. Even locking and unlocking the door didn't unlock the fuel door, I had to turn the car back on, lock the doors, turn the car off, then unlock the doors. Why is opening the fuel door so complicated? There doesn't seem to be any way to do it mechanically, so good luck when the solenoid dies.