Ok, have got to this stage which has added a text box but not sure how to echo the info from the text box into the message? Is it possible to replace the word ‘hello’ below with the details entered into textbox1?

add_filter( 'fep_form_fields', function( $fields ){
	$fields['cus_fep_textbox1'] = [
		'type'     => 'text',
		'where'    => 'reply',
		'priority' => 22,
		'label' => 'Start Point',
	];
	return $fields;
});

add_action( 'fep_action_message_after_send', function( $message_id, $message, $new_message ){
	if ( ! empty( $message['cus_fep_textbox1'] ) ) {
		fep_add_meta( $message_id, 'cus_fep_textbox1', $message['cus_fep_textbox1'], true );
	}
}, 10, 3);

add_action( 'fep_display_after_message', function(){
	if ( fep_get_meta( fep_get_the_id(), 'cus_fep_textbox1', true ) ) {
		echo hello;
	}
});