@ChenBr When you say you’ve read various forum threads, have you read this one?
Specifically this section:
Since you mention using Vue, my guess is that your pages are being client side rendered and thus that there is no HTML form within your HTML file/s for Netlify to have discovered during their post build processing.
For example your /index.html
looks like this:
There is no <form>
there at all obviously, as it’s being generated at runtime via the Vue code.
As mentioned in the text from that thread, you will need to have a HTML file in the build output that contains a version of the form, so that Netlify can detect it.