Canned responses do not do forms. They are simple text with light html (links, fonts, colors, images).
Users do not "sets the canned response", only agents can select a canned response.
If you want to add a form to a ticket you can either add it at the Ticket Details Form, via Help Topic, or Agents can add them manually. It would not be in the reply text area, and would not be sent to the User who owns the ticket or any Collaborators on the ticket.