Posting user meta in registration form on Membership Plugin

Hi All,

I've registered custom user_meta fields to WordPress using Codex guide with no issues. I have then added them to the account update page with no issue as I simple declare them in $user = array in account.form.php

What isn't clear to me however is how to add them to registration.form.php

I can add the input fields but I am struggling to work out where I need to place my update_user_meta

I think it might be somewhere in membershippublic.php but I could be wrong.

Tearing my hair out so would appreciate any pointers or ideas.

I have searched the forum but all posts seem to reference either old code or buddypress (buddypress isn't an option due to client requirements).

Thanks