My Form doesn't display

Hello,
I just installed Dynamic Text Extension but when I add the field [dynamictext premio “CF7_referrer”] my form doesn’t display. I mean, without that field when I go to the page where the form is I can see it with all the fields, but when I add the dynamictext and reload the page the form just isn’t there.

Can anyone help me, please?

https://wordpress.org/plugins/contact-form-7-dynamic-text-extension/