@Mangonster The EA App doesn't have a function to move games, but Origin does. So please install Origin; you can have it and the EA App installed at the same time as long as they're not both running at the same time. If you get an error when trying to open Origin, restart your computer.
Once Origin is installed, open your game library, right-click on the Sims 4 icon, and select Move Game. Then select a folder on your external drive. Origin should take care of the rest, but it's still a good idea to run a repair (the option is in the same right-click menu) afterwards.
Just to be clear, the above is about moving the game's program files alone. If you'd like to move the user data—saves, saved households and builds, etc.—to the external, that's a separate process covered here:
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