If you want to make an app available to a site without requiring users to install it, you can deploy it by following these steps:
- While logged in as an administrator, navigate to the App Catalog site.
- Select Site contents. If your site collection has been upgraded to the modern libraries and lists display, select the Return to classic SharePoint link.
- Select the ellipsis (...) next to the app you wish to deploy and select the ellipsis (...) in the popup window. Select Deployment from the menu:

- Enter the full URL of the site collections to deploy the app to and click Add. Under Available managed paths, select ...