No alerting message saying that uploading an image is required

Hey guy!
I have created this form for a client where it’s required to upload an image.
However, when trying to submit there simply no reaction when pressing the button.

No message pops up saying that uploading an image is obligatory to finalise the submission. similar to this one

What can I do to change this?
Thanks in advance!

Here is my site Read-Only: LINK
(how to share your site Read-Only link)

Hi @cipriano, thanks for your post, could you help to share the file upload settings for your upload element in the form?

Would it be possible for you to help share some additional detail that will help the community to provide assistance?

Thanks in advance