Cpanel have implemented 2 Factor authentication for Cpanel and WHM. This is not enabled by default as some of the plugins and third party programs that integrate with Cpanel via API have not yet updated to work with this and if you enable it, it may fail. For example WHMCS billing system integration with Cpanel.

You need Google Authenticator or Duo Mobile installed on your Android or iPhone to get 2 Factor Authentication working.

You can find more more information on how to enable 2 Factor authentication in cpanel on cpanel docs

https://documentation.cpanel.net/display/ALD/Two-Factor+Authentication