Add "Waiver Agreement" fields to campaign form on initial submission

functions.php

<?php 
add_filter(
	'charitable_campaign_submission_fields', 
	function( $fields, $form ) {
		$waiver_fields = array(
			'legend'   => 'Liability Waiver and Release',
			'type'     => 'fieldset',
			'fields'   => array(
				'waiver' => array(
					'type'      => 'paragraph',
					'priority'  => 1,
					'fullwidth' => true,
					'content'   => 'My Waiver',
					'editable'  => false,
				),
				'waiver_agreement' => array(
					'label'     => 'I read and agree to the liability waiver.',
					'type'      => 'checkbox',
					'value'     => 1,
					'priority'  => 2,
					'required'  => true,
					'checked'   => $form->get_campaign_value( 'waiver_agreement' ),
					'data_type' => 'meta',
					'fullwidth' => true,
					'editable'  => false,
				),
			)
		);

		$waiver_fields = $form->filter_non_editable_fields( $waiver_fields );

		if ( ! empty( $waiver_fields['fields'] ) ) {
			$fields['waiver_fields'] = $waiver_fields;
		}
		
		return $fields;
	}, 
	10, 
	2
);