Advanced documentation of the Contacular API should help you if you want to do a little tweaking
Contacular is object orientated by design and consists of a primary 'ContacularForm' class. This class contains both public and private functions. For most implementations, you will only need to call the public functions, allowing you define the propeties of the form you desire and toggle various options on and off. The private functions are used primarily for internal construction of the form content, data handling and validation logic.
Prior to any function calls, you must include the 'contacular.php' file within your document, and instantiate a new 'ContacularForm' object. This can be done with the following code. Please note that the inclusion of the 'contacular.php' file is not shown in most demonstration and example code as the prior inclusion of this file is already assumed.
include "contacular.php"; // Include the main 'contacular.php' file
$form = new ContacularForm("simple"); // Create a new Contacular Form
In this example, we include the main Contacular file and instantiate a new ContacularForm with the name $form, using the 'simple' Contacular form type. Contacular form types define the preset arrangement of fields that are present within the generated form. There are many preset Contacular form types, along with the special 'custom' Contacular form type which allows you build a bespoke contact form from a blank slate.
After the initial instantiation, processing of form response, output of the form HTML code and other options are taken care of by calls to the new object's public functions. All Contacular public functions, including their purpose, arguments and return value(s) are described in full within the contacular.php code comments.
One of the best ways to learn if from example - so make sure to take a look at the Contacular demonstrations. Each demonstration shows the associated source code used to produce it.
If you need any assistance integrating Contacular, feel free to make contact.