Wordpress Plugin: How to Pass extra fields?

Use Case: A Local Blog For Marketing a real estate firm. All of the content is behind a (free) paywall that requires the user to sign up for the website to view.

The Wordpress plugin passes the first name, last name and email address. I am assuming because these are default user meta fields.

I want to pass the user’s phone number in some way. The issues that I see are 1) adding user meta field 2) collecting it at sign up (my theme doesn’t support collecting the phone number by default) and 3) how to pass the phone number to the mautic contact field.

Has anybody done something like this?

I’ve moved this to #3rd-party-addons as that’s a more appropriate place.

I’ve pinged one of the community maintainers on the Wordpress repo to see if they can give any insights.