You may decide that you want to set up an additional Project Online site, to manage projects in a separate environment from your first Project Online site. You can do this by creating another site collection with Project Web App.
Note You can have up to three separate Project Online sites with your license. If you need to free up a Project Online site to make room for a new one, you can delete a Project Online site.
To set up another Project Online site:
Tip If you’re not sure of your User ID, refer to the ‘Get Started with Microsoft Office 365’ email message that includes your User ID and other information about your account.
For example, select https://contoso.microsoftonline.com from the Public Website Address list, and then type pwa in the box next to the address. The address for the site collection will be https://contoso.microsoftonline.com/pwa.
Note After setting up the site, wait 15 minutes before using it, so that Project Online can finish installing.