Allow users to upload/access folders that are created or already created

[EquipableMC]

I have some pre-created folders I have made for myself, and recently I gave my friend access, and he couldn't access any of the folders and I found no way to add him to them, so I just gave him admin and let him create his own folder, I feel like folders should be shared publically as an option (obviously this comes disabled to already created folders, could possibly be a setting even).