Dial in migration from Twilio

We are in the process of migrating from Twilio video to Zoom video.

One of the main features we provide is for a participant to join a session using a phone instead of a computer microphone for audio. We use the dial in method where a user has to call a number and enter a PIN to connect to a session.
In order to associate our internal user with the Twilio dialed in user we create a custom PIN for that user to enter while dialing into the Twilio phone numbers.
Twilio calls the webhook to which we have a listener for and we validate that the PIN is valid for this session and that the user has access to it. We then pass the necessary internal user data to Twilio in order to trigger a participant connected event on the frontend side of things which will have all the custom user data for that user to be displayed.

Is there an equivalent webhook with Zoom for when a user is dialing in?
Is there a way to control the authentication process and also pass custom data to Zoom for the joining user?
Twilio also provides a way to customise the automated welcome message when dialing in. Does this exist for Zoom?

Thanks

Hi,
The meeting.participant_data event should give you more data on how the user has joined the meeting.
While I know its not exactly what you are looking for it may hopefully help in some manner.