You can limit who can use ApeksOPS by going to ApeksOPS > Settings > Security and entering a list of comma-separated WP login names in the field “Grant ApeksOPS access to these users only”.

You can limit who can use individual pages by going to ApeksOPS > Settings > Security and turning on the option “Control Access At Page Level”.  A list of available pages will be displayed.  Enter the WP login names for people allowed to use each page.  (NOTE: leave blank to allow all to access a particular page).

NOTE: If the WP user has WP Administrator access, the above settings do not apply.  WP Administrators can always access ApeksOPS and can access all pages regardless of the above settings.