Mailchimp Woocommerce Sync behind firewall

Hi,

I have a site hosting behind the firewall, it could not sync successfully.

Please advise any ports other than 80, 443 are required for the sync operation?

Below is the log from MailChimp.
2020-10-20T04:19:58+00:00 NOTICE mailchimp-woocommerce-sync.started :: Starting Sync :: Tue, Oct 20, 2020 4:19 AM
2020-10-20T04:20:04+00:00 NOTICE flag.store_sync :: <p>id: Read-only field ‘id’ supplied.</p><p>list_id: Read-only field ‘list_id’ supplied.</p><p>name: Please enter a value</p> :: in /wp-content/plugins/mailchimp-for-woocommerce/includes/api/class-mailchimp-api.php :: on 1885

Regards,

Venom