If you do not want your app to be publicly available for everyone, you have two options for how to distribute it:
Custom app distribution – This option is available in the “Pricing and Availability” tab in the Product Page. You can select the app distribution to be private. Then, you provide a list of organization IDs or Apple IDs for which the app should be visible in the store. Working with Apple Business Manager, Apple School Manager, or redemption codes, you can distribute the app only to specific clients.
You can learn more about this kind of distribution here.
In-house distribution – using the Apple Developer Enterprise Program you can create provisioning profiles and certificates in order to distribute the app internally in your company. Keep in mind that the Enterprise Program costs 299$ annually.
The enterprise program is dedicated to companies that want to develop and distribute the app internally for employees.