communiscats Your commands are incorrect in a few ways. The point of including %UserProfile% in the command (and with the second % at the end) is to tell Windows "apply this to the current user profile." You can't insert your actual name here; Windows won't know what you're trying to tell it.
You also cannot create a symbolic link called "The Sims 4" that points to an Electronic Arts folder, as your command is trying to do. The game won't be able to figure this out.
Your second command also has a shorter username, like maybe you left out the last letter.
And you've put the path "E:\The Sims 4" in your command, but that only applies if your external drive has the letter E and you have a "The Sims 4" folder directly on it.
Please list the full path to the folder on your external drive that you want to link to (the Sims 4 or Electronic Arts folder; either is fine, but I need to know which you'll be using). Right-click the folder and select Properties > General, then list the Location. Please also open the game and list the location of the user folder it's reading, as described here:
https://sims4.crinrict.com/eng/2018/07/how-to-find-your-user-folder/
I will write out the command for you to use.