This works by storing a shared secret key in your encrypted KeePass database and using that information coupled with the current time to generate rolling codes that can be entered into the verification system.
-In order to use this plugin, Add a key called OTPAUTH in the advanced section of the entry dialog. The value of this key should be a base32 encoded secret key. Google provides a base32 encoded key so you could enter it in here in addition to setting up the app on your smartphone.
When enabling TOTP on your verification system, you will be provided with a key. Often this comes in the form of a QR code. In most cases you can also get a base32 encoded key as well. This can be of varying lenghts. Once the plugin is installed, every entry in KeePass will have a new option labeled "One Time Password" in the context menu of the entry.