The NS Cloner plugin offers a built-in step by step process for creating a clone of a site. Follow these steps to clone one of the sites in your multisite network:

1. Log in to the WordPress Dashboard as a super administrator.
2. Click the NS Cloner menu item on the left menu.

3. You will see the following screen. From here, you can configure the cloning process:

4. Select Standard Clone for the Select Cloning Mode setting.
5. Select the site you want to clone for the Select Source setting.
6. Add a title and a unique URL for the site in the Create New Site section.
7. Click the CLONE button at the bottom to clone the site.
8. You will see the following screen, which shows the cloning process:

9. Once cloning is completed, you will get another screen with the result of the cloning process:

Now, you should see a copy of the selected site in the Sites section of your multisite network.