Whitelist IPs to access website – [CMP – Coming Soon & Maintenance Plugin by NiteoThemes] Review

Hi there, I have not found the option to set upo an array of IP Adresses, that should see the webpage as if it was open to public. I need to test a plugin that needs to connect to an external server for testing purposes, however for the public, the maintenance should be still working….

how can I do that? thanks