Installation directory move database is not recognized?

I wanted to move the installation directory of Just Cause 3 on Steam, but when I clicked on the tab, I was only shown the internal memory card on which the save game is located.
However, the internal storage space is very full, so I bought an external memory card, which I'm plugged in and installed Just Cause on. However, with all games, I always have the problem that the game saves not on the external memory card, but on the internal memory card, which is completely full.
When I try to move the installation directory, the external memory card is not displayed