Advanced ModSecurity Rules by Atomicorp subscription was bought for Plesk and appropriate extension was installed. Why does it ask for username/password when switching to Atomic ModSecurity (subscription) ruleset?
The Atomic ModSecurity (subscription) ruleset is intended to use when a license is purchased directly from https://atomicorp.com.
If a subscription was bought from Plesk, the Atomic Professional ModSecurity rule set should be selected in Tools & Settings > Web Application Firewall (ModSecurity) > Settings page. This option does not need a user account on Atomic website.