The Strait of Hormuz is unlikely to be closed for long. Even if Iran tries, it has no legal right under international law (UNCLOS), and such a move would hurt China more than the US.
The U.S. and allies could legally respond militarily to reopen it, but escalation risks remain. Given Iran's own reliance on the Strait, any closure would likely be brief due to international pressure and military action.
Iran is in serious trouble. The regime doesn't have many options left. All options are suicidal.