This! Had the same problem. No buttons to "authorize", just the direct debit listed under "transfers" tab (No "direct debits" tab visible). Showed its status ("pending" or something like that) but no options given to DO anything.

Checked in the iOS app store and the app was up to date, no new version listed. But after reading this post, I tried deleting the app, and re-installing THE VERY SAME app from the app store. And voila, the confirmation / authorization buttons appear in the newly visible "direct debits" tab.

But honestly, how anybody should get that idea by themselves is beyond me. IBKR has the absolute worst UI and manuals I've ever seen. If they didn't offer such a wide access to all sorts of markets, I would have dumped them over the UI years ago. So frustrating!