Inserting it into a post

I love the way the contact forms look with this plugin, but for some reason, I can’t ‘insert into post’. It may be due to the fact that I am using an ‘Elegant Themes’ Theme and using their modules to build my page. However, even when I disable those modules and use the standard text box, it gives me the option to insert a form, but doesn’t actually insert it. Am I doing something wrong?

https://www.ads-software.com/plugins/custom-contact-forms/