For reference: This would almost triple their govts funds each year. One must also not forget that they're able to raise tolls in the future, both for monetary investment but also for negotiation purposes.
5D chess!
Most importantly Iran can't afford to keep the strait closed to enforce this. If they block shipping their own will be blocked as well - which hasn't yet happened, they were still allowed to ship oil. Iran was already in terrible financial shape before the war and they aren't negotiating from a strong position of power to take those risks.
Why do you say this? During the war they set up a checkpoint system so their ships and ships they allowed to pass could still pass through.
If that is agreed upon it's going to come with some concessions by Iran which is even less likely.
USA could agree to it because it's not particularly dependent on that fuel supply and therefore would only pay the costs indirectly via market forces, which as the thief-in-chief pointed out, does (the parts he cares about of) their economy no harm as a net petroleum-product exporter, and above all else, they are losing the war.