Is it possible to do Invite-Only Passwordless authentication?

I see that it’s possible to disable signups as part of a password-less connection. This is also implied by @prashant answer to this question: How to prevent users signups in Passwordless connections? - Auth0 Community

However, I don’t quite understand how to create users in password less connections. When I try to create a user in the dashboard, it only allows me to select database connections. My email passwordless connection doesn’t appear anywhere. Is API the only way to create a user into the passwordless connection?

Passwordless users currently can’t be created from the Dashboard; they can be created via the Management API:

Using the management API, how can we control what client the new passwordless user will be authenticated with (when they click on the magic link from the received email)?

Using the /passwordless/start endpoint of the authentication API requires passwordless signups to be enabled afaik (even if called from the server)