I’ve run upon this problem from time to time, what has helped me is to update ther repoistory. Just dont remember clearly how i didi it. So this is from my memory + guesses wehre the memory lacks:
Open Settings->Add-on browser->My addons->addon repository-
Here you move the “cursor” to Kodi repository, open contrext menu (three lines button on OSMC remote, C on a keyboard), then chose check for updates.
When that is done, restart kodi and you shoul be able to install depends automatically.
Hope that helps.