@Obinna_Ukwueze If the site has no data, you may delete existing site and create new sites:
Step1: Delete existing site
bench drop-site site1.local
bench drop-site site2.local
Note: Execute this from frappe-bench folder. You need root mysql password. This will remove site and and database completely. In case of any issue in site_config.json you may get some issue. Check error in case of any.
Step2: Create new site
bench new-site xyz.domain.com
bench new-site abc.domain.com
Note: Use actual domain/sub-domain as site name which will be used for erpnext users.
Step3: Once again install erpnext app for new site
bench --site xyz.domain.com install-app erpnext
bench --site abc.domain.com install-app erpnext
Step4: Setup production
bench setup nginx
sudo service nginx reload
sudo bench setup production vm_user_name_goes_here
Note: Reconfigure nginx server once to avoid any configuration issue.
Sunil