You can take a note of the credentials and use them to operate your bike box directly at the terminal
4.5 What can I do if I can no longer get my bike out of the bike locker because my mobile phone is no longer working / I have forgotten my mobile phone / the battery is flat ... and I can no longer access the code?
If your mobile phone isn't working, you can still access the booking details, including the bike box access credentials, from the email sent to your user's email address.