If you are having difficulties accessing your Authentication App or the code on the app, you will be able to get a back up code sent to your verified mobile number connected to your username.
To access the back up code by mobile number:
Click Log In in the top right of the TryBooking website
Enter in your correct email username and password
On the Multi-Factor Authentication screen, select Login with one-time SMS code instead
A SMS text message will be sent to the mobile number indicated on screen. Enter the code into the Verification Code field, and click Log In
If you are needing to re-establish your TryBooking authentication code on your Authentication app, you can do so by disabling Multi-Factor Authentication, and then re-enabling it once more. Please see: Multi-Factor Authentication