This is the Instant Pot method. Pressure cooking allows this to be done in like an hour. You can place the can in a pot with water and boil it very slowly for about 3 hours or so to get similar results, but fuck that.
What's in it
Condensed Milk
What to do
Remove label from unopened can of condensed milk and place inside the instant pot on top of the wire wrack.
Bring water level to just under the top of the can
Set to Manual/Pressure Cook for 35 minutes, close lid and make sure valve is sent to sealing
Let Instant Pot do it's thing. When 35 mins is up, turn off and use quick release pressure method, then remove lid for 5 minutes.
Start progress again, but when next 35 is done, turn off but then release pressure naturally, typically 15 mins.
Remove lid, LET CAN COOL DOWN COMPLETELY BEFORE OPENING.