sims 4 won't open, installed on external hard drive

Hello, I have been looking through countless pages to find out why my sims 4 will not open. I hav downloaded it on to an extended hard drive, I have a 2020 MacBook Air. I have been trying for weeks not to get my sims 4 to properly work on my extended storage. I have the sims 4 game copied onto my extended storage, the Electroic Arts folder, The sims 4 packs, and my mods. I have completely removed the game from my actual computer. I have made sure the correct pathway in origin has been taken; /volumes/extended storage/the sims 4 app. At first the game was opening, but saving onto my internal hard drive, I tried to fix that (i think I did) but I’m not sure, my mods would not show up originally but I’m not sure if this problem is fixed either. The game will now not open which makes me think I correctly put it onto my extended storage because now the game is not connected to my actual computer, but as I said the game will now not open. It just moves up and down in the dock and does not actually open the game. Can you please possibly help me out? 

I just tried to open it again and the Electronic arts folder is still appearing in my documents folder on the computer, as well as not opening still. I am not sure what I am doing wrong. Origin has full access, my extended storage if formatted properly. I’m sure it is a simple fix I am missing but I am unsure at this point. 

thank you so much for the reply, I have heard about making a Symlink for it to find the game, I will try my best to figure out how to do so. As for the game and documents, I am not sure. Is there a way to check that? 

I believe the game has access to the documents folder, In my extended storage there is the sims 4 game, the Electronic Arts folder, and the sims 4 packs, including my mods.

Just an update, I think my extended storage may not be formatted correctly. I am currently working on that but having issues. When i got format it, I cannot put in a scheme so I am figuring out why and how to fix it.

Hello another update sorry, I think I have properly formatted the extended storage now, I have it in APFS now. I am confused when it comes to moving the EA folder to my extended storage. I see it says something about USB, I am confused what this is referring too. I am unsure where to type these commands.