Enpass is an offline password manager and doesn’t keep any of your information or Enpass data on any cloud/server. Two factor authentication is used in online services where the requested data is transmitted after validating the user through a second factor (generally an OTP on phone or email) and works as an extra protection, which is not at all required in case of offline services as your data is with you only.
Lets consider for a moment, any how Enpass implements TOTP support (again, its a consideration), but how that OTP will be verified through server as we don’t have any information. Being offline is not a limitation of Enpass but gives you a peace of mind that your data is with you only. Also Enpass is an encryption software which recognizes your Master Password as the only key to get your data. So just think for a moment, if any one knows your master password why will he go into hassle of OTP stuff as he just need your database from device and open it using your compromised master password.