You may find yourself because you've received several harassing emails from Bionic Cat telling you to enable your 2-factor authentication for Google.
"But I've already set it up!!" you might say whilst cursing the Cats.
If this is you, please make sure you've actually enabled/turned on 2-factor authentication. Just by virtue of setting up an Authenticator App, 2-factor is not automatically enabled, which is a silly design by Google.
In short:
- Go to https://bionic.cat/Google2step
- Click on where it reads "2-step verification is Off"
- Turn it on
See below for a quick video on the process.