This is a 2FA QR code generator made in JavaScript that helps you make QR codes from 2FA secrets. Most websites give you both a QR code and an option to manually type the secret. If you need to decode a QR code to obtain the secret, click here. To use this app offline, click here.
Please note that the advanced options are not supported by the Google Authenticator app (all advanced options are ignored). Yubico Authenticator supports these advanced options.
In the Google Authenticator app, it will look something like this: