My account add a custom link

add_filter( 'woocommerce_account_menu_items', function( $items ) {

	return array_merge( [ 'meeting' => 'Book Meeting' ], $items );

} );

// Optional Redirection Approach
add_filter( 'woocommerce_get_endpoint_url',
	function( $url, $endpoint, $value, $permalink ) {

	if( $endpoint == 'meeting') {
		return 'https://calendly.com/websean/meeting';
	}

	return $url;

}, 10, 4 );

// Optional Endpoint Approach
add_filter( 'woocommerce_get_query_vars', function( $vars ) {

	$vars['meeting'] = 'meeting';

	return $vars;

} );

add_filter( 'woocommerce_endpoint_meeting_title', function( $title ) {

	return 'Meeting';

} );

add_action( 'woocommerce_account_meeting_endpoint', function() {

	echo 'CONTENT GOES HERE';

} );