Iran Rial is sanctioned, Russian Ruble is sanctioned, Chinese Yuan is not. So it makes sense that they would prefer this, because the entire globe can use it and won't have any issues. Also the reality is that Iran wants money for every passing ship, and if you have a tanker with carrying lets say 1 million barrels worth of oil, then we are talking about 90 million dollars worth of product there.
I am sorry but if you are not going to profit even 1-2 million from that enough to pay for Iran, then you are doing something wrong. Imagine the profit margins are so razor thin that even 1-2 million dollars makes you lose money, that's not okay at all. If Iran does this, the world has to just follow the rules of conflict, if they didn't want to, then they should have not missiled them.
Okay, Iran wants to charge a fee for every tanker passing through the Strait of Hormuz. The question is: could Portugal, for example, also demand a fee for every tanker passing through the Strait of Hormuz? I want to understand who has the right to collect money. For example, could I also demand $1,000 from every tanker-in cryptocurrency, no less!
Or, for example, could the UK demand payment from Iran for every electron passing through the electrical circuit in Iran’s power grid?

No? Why not?

What are the criteria for who can demand payment and who cannot?