You may find the following works:-
Turning off 2-Step Verification
- Visit the Using 2-Step Verification page under your Google Account settings. Sign in with your username, password, and verification code if prompted.
- Click Turn off 2-Step Verification.
- A pop-up window will appear to confirm that you want to turn off 2-Step Verification. Click OK.
Revoking and destroying passwords and codes to protect your account
If you used App Passwords to authorize applications to access your Google Account, we recommend you go back to using passwords -- rather than App Passwords -- to access these applications. That way, you can revoke your App Passwords so nobody else can use them:
- Visit the Authorizing applications & sites page under your Google Account settings.
- Click Revoke for any application or device whose code you want to revoke.
- For each application that you revoked an App Password, you'll need to reauthorize the application by entering your username and password, as you did before you turned on 2-Step Verification. You might not be prompted for this information the next time you use the application as some applications will take longer to recognized that an App Password has been revoked.
In addition, remember to destroy all backup codes that you had been using to verify this account.