Make users understand a deep link is both for download and in app use

I am using deep links in my app for joining to a group,and are the main way for it. I have worked hard to make the links redirect to store if app is not installed and if installed join the user to the group. The problem is that users don’t understand that the links are both for download and joining, and share instead of a single link, a link for the App Store, google play and for joining.

How can I make users understand this?

Thanks!