Delete a Staging Site
To delete a staging site,- Login to your MainWP Dashboard
- Go to the MainWP > Extensions > Staging page
- Locate the wanted child site
- Click the Manage Staging Sites action (you will be redirected to the page where you can see your staging sites for the child site)
- Locate the staging site that you want to delete
- Click the Delete action link
Source Article:
https://kb.mainwp.com/docs/delete-a-staging-site/