I activated the plugin, but still get the message: "Install the plugin to activate the firewall"

There is an easy way to fix this issue.

Usually, this is because for some reason we were unable to contact our server to process the activation.

In order to solve this, deactivating and then activating the plugin from the plugin list in the WordPress admin area should fix the issue.

If this still does not work, your host is probably blocking outgoing connections to our server, https://api.patchstack.com

Feel free to contact our support chat with this issue.