Hi Lane,
If you are able to upgrade to 2.2.14 we have added a button to the interface to run the sync manually.
Otherwise you can trigger the sync from the server command line by triggering the sync cron directly:
The exact command will depend on your server configuration and permissions but it will be something like this:
sudo -u www-data php [/path/to/webroot]/admin/tool/totara_sync/run_cron.php
Simon