Can’t edit or hide H3 title

I have added custom checkout section (it has H3 title – More information) using this snippet:

/*
 * Example Register Helper fields for Company, Referral Code, and Budget.
 *
 */

// We have to put everything in a function called on init, so we are sure Register Helper is loaded.
function my_pmprorh_init() {
	// Don't break if Register Helper is not loaded.
	if ( ! function_exists( 'pmprorh_add_registration_field' ) ) {
		return false;
	}

	// Define the fields.
	$fields = array();
	$fields[] = new PMProRH_Field(
		'Odaberi okus',							// input name, will also be used as meta key
		'select',								// type of field
		array(
			'profile'	=> true,
			'options' => array(				// <option> elements for select field
				''		=> '',				// blank option - cannot be selected if this field is required
				'Kroasan maslac'	=> 'Kroasan maslac',		// <option value="Kroasan maslac">&Kroasan maslac</option>
				'Kroasan ?okolada'	=> 'Kroasan ?okolada',		// <option value="Kroasan ?okolada">$Kroasan ?okolada</option>
				'Kroasan marelica'	=> 'Kroasan marelica',	// <option value="Kroasan marelica">Kroasan marelica</option>
			)
		)
	);
	
	$fields[] = new PMProRH_Field(
		'Vrijeme dostave',							// input name, will also be used as meta key
		'select',							// type of field
		array(
			'profile'	=> true,
			'options' => array(				// <option> elements for select field
				''		=> '',				// blank option - cannot be selected if this field is required
				'6:00-7:00'	=> '6:00-7:00',		// <option value="6:00-7:00">&6:00-7:00</option>
				'7:00-8:00'	=> '7:00-8:00',		// <option value="7:00-8:00">$7:00-8:00</option>
				'8:00-9:00'	=> '8:00-9:00',	// <option value="8:00-9:00">8:00-9:00</option>
				'9:00-10:00'	=> '9:00-10:00',		// <option value="9:00-10:00">&9:00-10:00</option>
				'10:00-11:00'	=> '10:00-11:00',		// <option value="10:00-11:00">&10:00-11:00</option>
			)
		)
	);

	// Add the fields into a new checkout_boxes are of the checkout page.
	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' );

The problem is that its H3 cannot be edited inside the snippet nor translated using Loco translate plugin like all the other H3 titles. It also can’t be hidden because when I try to hide it using custom css command then all the H3 titles from the page also get hidden.

Is there a way to change the text of that H3 or if not possible to hide it?

Thank you very much!
Toni

The page I need help with: [log in to see the link]