Getting started
To get started with this plugin please follow the instructions below.
1. Install and activate the plugin
Download and install the plugin from the WordPress plugin directory. You should do this for both the site receiving the metrics (the monitor) and the site sending the metrics.

2. Configure the plugin on the monitor site
Head over to the website you want to act as the monitor (the site receiving the information) log into the /wp-admin and head over to Settings > Sites Monitor.

Select Monitor as the type of website and hit Save. The page should now refresh and you should see a new tab (Custom Post Type) called Sites. There is no manual action required there, it’ll empty for as long as we haven’t synchronised anything.
3. Create a application password on the monitor site
Now go to your user settings and create a application password, you can pick any name you like. This step is only required once, you can use the same application password to connect your sites to the monitor.

Hit Add New Application Password and store it because we’ll need it in the next step.
4. Configure the plugin on the site
Head over to the site which we want to be monitoring and go to the Sites Monitor settings at Settings > Sites Monitor.

Select Site as the type of website and fill out your connection settings, the username is your WordPress username on the monitor site and the application password is the one we generated in the previous step. When you’re satisfied with the settings hit Save.
If you see no errors the site should be successfully connected.
5. Final steps on our monitor site
Now back to our monitor site we can verify if the synchronisation went well by visiting our Sites tab (Custom Post Type). It should now have an entry.

5.1 Flush permalinks
Because this this plugin registers a new Custom Post Type, we should flush the permalinks. We can do this by visiting the Settings > Permalinks page on our monitor site. A visit should be enough we do not need to save the page.
Note: flushing permalinks is a common practice with WordPress when you register a new Custom Post Type which registers its own route (in our case /sites/<id>).
5.2 List the sites on a page by using the Gutenberg block
As the final step we can add the Sites Monitor List block to a page to create a overview of all our websites. Add or edit a page and search for the Sites Monitor List block. Hit Publish or Update and view the page.

6. All set!

🎉 You have now set up the Sites Monitor plugin and you can now monitor your websites. Clicking on a site will take you to the detail page giving you more metrics.
Seems like a lot? Well most of this was one time only
Configuring the monitor site is only something you would have to do once. With your next websites all you have to do is connect them (step 4) and you can skip the other steps.