He said that the tariff is $1 per barrel of oil, adding that empty tankers can pass freely. “Once the email arrives and Iran completes its assessment, vessels are given a few seconds to pay in Bitcoin, ensuring they can’t be traced or confiscated due to sanctions,” Hosseini added.
Considered international by people who want to pass through the strait without paying.
It’s considered international by international maritime law. Free passage, freedom of navigation is essential to trade and commerce.
Iran‘s attack on international shipping is a breach of international law and an act of war.
A blockade can be legal under international law, but it’s always an act of war. Demanding a toll to pass means it’s not a legal blockade.
There is no such thing as international law if countries don’t agree to it.
For example the United States has laws and policies designed to prevent the arrest of U.S. personnel and its allies by the International Criminal Court (ICC). The 2002 American Service-Members’ Protection Act (ASPA) authorizes the US President to use “all means necessary and appropriate” to release U.S. or allied personnel detained by the ICC, often termed the “Hague Invasion Act”.
A quick google search will give you the history.