I have downloaded the expansion but it will not load
Some information about how you are trying to access Storm Island and what exactly is happening when you do would help.
You need to progress further into the game to access it.
I press the pause menu and I cannot select it’s tab
Like others have posted you need to progress to a certain pont in the game, at which point you will get an icon showing at the docks which will allow access to Storm Island.
You need to complete 3 championships in the game first and then you’ll be prompted to go to Storm Island.
Yes, if it is three championships that means it is after the first award party and is likely that the third or fourth championship is in Nice Masséna (which is the area where the Isola della Tempesta access point is).