How to submit custom form data using ajax to HubSpot form?

You can’t do it easily. You can send AJAX requests only to the same server your site is on.

To send such request to another server, you’ll have to use CORS (https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS).

And I don’t believe that HubSpot will allow you to set proper headers…

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)