Help adding one-time-password?

[Kirika-]

First, make sure you have the official version of the app for your phone directly from Google Play or Apple Store.... third party sources might be a fake trojan app.

There should be Accept and Decline on screen buttons and the bottom, on the Android version from Google Play.
If you do not see them, reboot your phone to see if that clears any glitches.
As you said "I just got a new phone", make sure it's OS is fully up to date and that, for the Android devices, all the Google apps and Google system software is also up to date.

If you have a iOS device, try rebooting and updates, but I do not have hands on knowledge of Apple devices to further help.