Hi, @joaosalgueiro. The link to the path you shared is not a static HTML file. The HTML is returned by a serverless function. We require a static HTML file with the form definition for the form handler to be created.
You can see the function returning the HTML here:
https://app.netlify.com/sites/mzsite/functions
This means, there is no HTML form for the build system to process. This is a requirement for the Forms feature as covered in our documentation here:
https://docs.netlify.com/forms/setup/
Quoting the very top of that page:
Netlify comes with built-in form handling that’s enabled by default. Our build bots do it by parsing your HTML files directly at deploy time, so there’s no need for you to make an API call or include extra JavaScript on your site.
If you don’t have the form in an HTML file, there is nothing to process during the build and no form handler is created.
The solution for this will be to copy/paste that form into an HTML file and then deploy that HTML file with other static files being deployed with this site.
Visitors do not need to use the HTML form. The HTML file is just used to create the form handler.
The form being returned by your serverless function can be used for submitting the form. Note, it is important to keep the name of the form and the list of inputs in the HTML file in sync with the serverless function version. However, if they do match, the function form will work for the form submission.
Again, though, for the creation of the form handler, a static HTML file containing the <form> tag and its <input> tags is always required.
Also, you can even make a redirect rule that makes the HTML file with the form return a 404 for site visitors. Even if the form HTML file is a 404, the form handler will still be created (again, provided the file exists).
This is because our build system is looking at the static files in the publish directory and not the deployed site itself. For this reason, the HTML file version form does not need to be accessible to visitors. However, it must be in the publish directory when the build completes or our form processing will not see it. Again, when the HTML is generated by a function (which yours is) there is no static HTML file in the publish directory.
Please let us know if there are other questions or if there are difficulties making the static HTML file with the form.