Step 2, demand compliance.
Step 3, upon not hearing of compliance, levy fines.
Step 4, upon non payment of fines, declare in breach of (2).
Step 5, block site from UK using DNS, in the same manner as torrent sites etc.
5 was always the goal, 2 to 4 are largely just performative.
#2-#4 are the government trying to impose its national laws on an entity in a completely different country, operating entirely in that completely different country, with no business relationship whatsoever with your country. It's a futile and frankly rather insulting effort; no different from if Iran declared it was illegal for UK women living in the UK to leave the house without wearing a burka.
#5 is an authoritarian offense against your own citizens; trying to prevent them from being able to communicate with people in another country even if they want to do so.
I know it's an odd nitpick, consider it a compulsion of mine.