If you use Bitwarden for MFA, it will generate the 6 digit OTP for you to login to websites and services.
If you're getting an error from the site/service you're using to tell you that the code is incorrect, check the date and time on whichever device you're using Bitwarden on. OTPs rely on data from the time on the device, and if this is incorrect, your OTP will not match up and you won't be able to login. If you have an issue with your time, please contact the service desk and they will be able to assist with this.