# System Settings
You can localize ERPNext to use particular timezone, date, number or currency format and also set global session expiry via System Settings.
By checking the 'Allow Login using Mobile Number' checkbox, you can login to ERPNext using a valid mobile number set in your User account.
To open System Settings, go to:
> Setup > Settings > System Settings
####Two Factor Authentication.
Settings for Two Factor Authentication can be configured here.
* Select the authentication method to be used
* Expiry time for QRCode image if "OTP App" is selected in method
* Issuer name of the One Time Password
{next}