Save Contact Form 7 Data into Custom Table – Updated

function contactform7_before_send_mail( $form_to_DB ) {
	$form_to_DB = WPCF7_Submission::get_instance();
	if ( $form_to_DB ) {
		$formData = $form_to_DB->get_posted_data();
		$FirstName = $formData['FirstName'];
		$LastName = $formData['LastName'];
		//... code will begins  
	}
}
remove_all_filters ('wpcf7_before_send_mail');//optional
add_action( 'wpcf7_before_send_mail', 'contactform7_before_send_mail' );