Horizon is not allowing me to drag modded gamesaves into the area

when I try to drag a modded gamesave into the gray area its not allowing it, when I try to inject it says invalid stfs package and I don’t know what to do.

Is it a save that you downloaded? It’s most likely in a .rar or .zip container, and needs to be extracted before you can add it with Horizon. Try to open the folder/container, and drag the file you find inside of it out to your desktop, and then try dragging that file into Horizon.