"For two factor authentication, please follow the steps below:
1. Open the Shell App and log in.
2. Tap on “More” in the bottom right menu.
3. Go to "My Account".
4. Go to “Security”.
5. Two-factor authentication via SMS is turned On - turn it off.
6. Enter your password for verification.
7. Return to the "Security" page by repeating steps 1-4.
8. Turn ON two-factor authentication.
9. Enter a new phone number and verify.