I can’t set the fields as required

Good morning, on a website, I am using a combination of the Contact Form 7 plugin with the Contact Form 7 – Post Fields plugin. I am unable to make the fields I create with Contact Form 7 – Post Fields required. Here’s an example of how I have configured the field. Not only does it not appear as required during submission, but there is also no alert message displayed. How can I do it?