my_pmprorh_init_custom_field.php

<?php

/**
* For more information on the Register Helper Add-on please visit https://www.paidmembershipspro.com/add-ons/free-add-ons/pmpro-register-helper-add-* checkout-and-profile-fields/
* Add the following code to your PMPro Customizations Plugin - https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/

**/

function my_pmprorh_init_custom_field()
{
    //don't break if Register Helper is not loaded
    if(!function_exists("pmprorh_add_registration_field"))
    {
        return false;
    }
    //define the fields
    $fields = array();

	
	// TEXT AREA
    $fields[] = new PMProRH_Field(
        "info_about_us",             // input name, will also be used as meta key
        "textarea",                    // type of field
        array(
			'label'	=> 'How did you hear about us',			// custom field label
			'required' => true, // make field required, set value to false to make it optional
			'size'		=> 100,				// input size
			'profile'	=> true,
			'addmember' => true,
			'memberslistcsv' => true,

        )
    );
	


    foreach($fields as $field)
        pmprorh_add_registration_field(
            "checkout_boxes", // location on checkout page
            $field            // PMProRH_Field object
        );
    //that's it. see the PMPro Register Helper readme for more information and examples.
}
add_action("init", "my_pmprorh_init_custom_field");