Example of Paid Memberships Pro - Register Helper Code. This code registers the Register Helper Field

rh-example-code.php

<?php

/*
* EXAMPLE ONLY of Paid Memberships Pro - Register Helper Code.
* Paste new Register Helper Fields above this line(s) of code in your PMPro Customizations Plugin
*/

$fields = array(); // this line should not be added a second time if you have previously declared it which i believe you have if you are trying to use this code recipe
	$fields[] = new PMProRH_Field(
        'field_name',		// input name, will also be used as meta key
        'text',			// type of field
        array(
           	'label' => "Label", 		// label of your field to be displayed
           	'required'  => true,    	// make this field required
           	'profile' => true,      	// show in user profile
        ));

foreach ( $fields as $field ) {
		pmprorh_add_registration_field(
			'checkout_boxes', // location on checkout page
			$field            // PMProRH_Field object
		);
	}