postfix cannot install dkim -unit not found

Hi

 I got problem for installing dkim service. I go on Postfix manager, click on the add dkim and spf.. rebuild. And it result into :
Failed to restart opendkim.service: Unit not found.

 So is there a package missing ? I was just a plain install and nothing change over the main cwp install. running on : CentOS-7-64bit.
How to install it manually ? or ..

Thanks in advance

As far as I remember, this was a bug introduced after the new version of UI was introduced in November 2017 - then administrators of CWP wrote that there was a patch for the bug, but that they would fix the bug in 'a coming release'

However, no Administrator has updated the Changelog, neither on the CWP site or on Facebook, even though several 'releases' has been implemented since then, so affected users are in a Limbo here...

Igor or other CWP administrator: What is happening with this bug???

Checking the box - Installs DKIM & SPF, enables DKIM for New Accounts and Domains
Then clicking Rebuild worked for me.