Once you’ve created a Metrilo account, you can add as many projects - meaning websites - as you want.
It’s super simple:
In the main menu in your Metrilo account, you see the name of the first project you’ve integrated (top left corner).
Hover over the name and you’ll see a “+ New project” button for adding more projects.
Click on it and integrate the new store.
From this place in the Menu, you will be able to switch between projects anytime.