Opnsense installation - unclear on how to install & enable

Following https://defguard.gitbook.io/defguard/admin-and-features/setting-up-your-instance/gateway#opnsense-plugin
Im unclear on if this is a step to be done on its own or in conjunction after installing the main gateway package.

After following the documentation above, I have installed only the "opnsense-plugin" package. I can see the configuration that exists in the Opnsense gui under VPN. However filling out the settings etc I receive the error "Endpoint not found" and at the top I see "Action not allowed or missing"

So my assumption is that the installation of the plugin alone isnt sufficient, I'd need to install the FreeBSD gateway package too?

Im quite impressed with Defguard's mission and would be happy to contribute to documentation.