Here in Alberta, it's the law that you need to pay before you pump[0]. If you're at a modern pump you insert your card, it does a preauth for some amount (you can select common amounts, like $20 of fuel, or "fill up" which is like $125 or $250 depending on the station), then when you're done it does a purchase for the exact amount.
If you're not at a modern pump, or you're paying cash, you have to go into the store, prepay for something that you think will fill your tank, fill your car, then go back into the store and get your change.
US is the same, except the pre-auth is set by the gas station owner, so you may need to go inside to pay with a debit card with less than that amount, and large trucks need two transactions to fill up
Here in Alberta, it's the law that you need to pay before you pump[0]. If you're at a modern pump you insert your card, it does a preauth for some amount (you can select common amounts, like $20 of fuel, or "fill up" which is like $125 or $250 depending on the station), then when you're done it does a purchase for the exact amount.
If you're not at a modern pump, or you're paying cash, you have to go into the store, prepay for something that you think will fill your tank, fill your car, then go back into the store and get your change.
[0] https://calgary.ctvnews.ca/station-owners-and-gas-and-dash-v...