See the information from Google support in: https://support.google.com/accounts/answer/7026266?hl=en&co=GENIE.Platform%3DiOS#zippy=%2Cyour-phone-isnt-nearby-or-you-cant-use-it
including the following from the "Your phone isn't nearby or you can't use it" section of that support article:
You might need to sign in a different way, like when:
- You don't have your phone.
- Your phone isn’t charged.
- Your phone is offline.
If you sign in with Google prompts instead of a password, you need to use your password instead.
- Sign in to your Google Account.
- Tap Use password or other options.
- Choose one of the options.
- Follow the on-screen steps.
If you use Google prompts for 2-Step Verification, try to sign in by following these steps:
- Sign in to your Google Account.
- Tap Try another way.
- Choose one of the options, and follow the on-screen steps.
Tip: The text in step 2 might be slightly different. The text may say, “I can’t do this,” or another message.