Custom CSS Form Problems

I hired a web developer that created a custom form in WordPress for a client. But, it has never functioned properly by sending the email with the contents of the custom form to the client. The developer has no idea how to make this work (and neither do I). It’s showing correctly on the website, but the submit button isn’t functioning by sending the contents of the form to the email address provided. Is this a simple coding fix or do I need to re-create all over in a form extension? I’m trying to avoid having to re-create because of time. Plus, it was created initially using Form Builder but the formatting was all off the page.

Also, I’m a Joomla girl. I don’t typically work in WordPress. So, I feel a little lost on how to proceed. Any help is appreciated. Trying to get this resolved for my client ASAP. Thanks!