When you do not want to change your existing forms and need total control over the look and feel with the data manipulation than the Pardot Form Handlers here is to your rescue, Pardot Form Handlers allow you to connect your external form with Pardot. You can use Pardot Form Handlers to collect the information by integrating the external forms.

Need to remember before integrating Pardot Form Handlers to existing form.

Set an Email Address field to be required on an existing form.
Both side fields should be the same as if a field requires on our form Handlers then should be required on our existing form too.

Let’s create a Form Handlers in Pardot.

In Pardot, Navigate to Marketing | Forms | Form Handlers

Click on Add Form Handlers.

Fill up the all Pardot required information.

Give the form Handlers a name.
Select a folder and add tags.
Choose your campaign.
Kiosk/Data Entry Mode: It allows you to submit multiple submissions on form without overwriting on your existing prospect.
Enable data forwarding to the success location: Does you data need to
Success & Error Location: Choose a redirect page for Error and a Thank you page.
Completion Actions: Add an action on prospects when they fill out the form.