Setup multitenancy, but the second website shows no erpnext application

The first website is running normally, bench --site erp2 to create a second website, Setup multitenancy, but the second website shows no erpnext application. Open only the Frappe framework. May I ask what is the reason?

Did you install the erpnext application to the new site?

bench --site second.local --install-app erpnext

You may need to uninstall this application and install it again.

bench drop-site second.local
bench new-site second.local --install-app erpnext