The Quickbooks Web Connector has a manual update button. This will restart the sync or "force" a sync between QuickBooks and JobNimbus. If you make any changes to records in either system, this will allow you to see if they will come through. QBWC is only for Quickbooks Desktop and is not applicable to the JobNimbus - QuickBooks Online sync.
Performing a Sync:
Prior to performing a manual sync, make sure your settings on QuickBooks Web Connector are set to auto-run every 60 minutes for optimal performance. The auto-run feature of QBWC will allow QuickBooks Desktop and JobNimbus to automatically sync in the background without having to be manually synced.
From within Quickbooks: