Override Meta Field

Hi, I would like to add a secondary email field when registering, but I would like to link it to another plugin meta field (‘_wmep_email_2’). So, when the user ends the order at the Woo checkout, this field is already completed.

I tried but ended up getting this error and the page gets frozen:

Uncaught SyntaxError: Unexpected token '<', "<p>Ha habi"... is not valid JSON
    at JSON.parse (<anonymous>)
    at Object.complete (user-registration.min.js?ver=2.2.6:1:9577)
    at c (jquery.min.js:2:28327)
    at Object.fireWith (jquery.min.js:2:29072)
    at l (jquery.min.js:2:80173)
    at XMLHttpRequest.<anonymous> (jquery.min.js:2:82499)

If I changed the meta field ‘_wmep_email_2’ works OK

Screenshot 1
Screenshot 2

Thanks