At present, there aren’t production and live environments for web apps (the progressive web app / preview show the latest version only), but it is really straightforward to push your app to TestFlight and test away, only releasing your finalised apps to App Store Connect. The Adalo documentation is comprehensive for this: https://help.adalo.com/testing-your-app/publishing-to-the-apple-app-store/start-your-build-in-adalo
For multi-tenancy, it depends what you are trying to achieve. It is definitely possible, though you’d need to give a little more information on your use case for anyone to help.
In principle, the two basic ways are using a different app for each tenant, all using the same database, or creating a tenant as a collection item and linking users to it, then managing the behaviour of the app based on the current tenant.