Close the preferences and try again. It should work now. You can turn back on the cookie protection when you finish connecting the places you need.
Safari browser is wildly known for protecting the users' privacy, but sometimes that creates some issues that limit normal usage.
We currently have a problem that prevents a user from connecting new places because, by default, Safari prevents cross-site tracking. So when you try to connect a place, you'll end up in the ikuTeam website, because the cookies we use are all blocked, and we can't take you back to the Team Files app.
There's a workaround you can use while we work on a solution for this. It's possible to deactivate the prevention of cross-site tracking in Safari's preferences:
Open Safari preferences.
Go to the Privacy tab.
Uncheck the "Prevent cross-site tracking."
Close the preferences and try again. It should work now. You can turn it back on when you finish connecting the places you need, as the rest of the Team Files app is not affected by this protection.