You may have multiple instances created on the Odoo online platform. Odoo's customer portal is designed in such a way that it can be used by customers to manage their instances or by Odoo partners to manage their customers' instances.

On the database management page, you can control access to other instances you were connected to, or you may revoke your access with those instances when they are no longer in use.

1. Managing your Odoo instance requires you to sign-in to the Odoo customer portal. Visit https://www.odoo.com/web and enter your username and password to manage your instances. Visit the My Databases page at https://accounts.odoo.com/my/databases. You will be able to see other instances as well, such as help and apps, besides your own instance:

As I am connected to the HELP and ODOO apps, they appeared in my databases; there are some instances hosted by Odoo to manage their online forum and the Odoo app store.

Clicking on MANAGE YOUR DATABASES will redirect you to the database management page:

2. Make sure you select the correct instance in the preceding image to duplicate it. Click on the DUPLICATE DATABASE button available to the right of the name to create a duplicate instance, enter the suffix name for the duplicated instance, and click on the DUPLICATE DATABASE button:

3. Similar to duplicating an instance, renaming an instance can be performed from the same page. Click on RENAME DATABASE, enter the new name of the instance, and click on Rename Instance; it is as simple as duplicating an instance:

When you log into your duplicated database, you will notice that the URL uses the same name you chose for your duplicated database. Duplicate databases expire automatically after 15 days: