If you are upgrading to Microsoft Dynamics GP from Microsoft Dynamics GP 2018 or 2016, there is no separate update process that needs to be completed for Flexicoder.  For Flexicoder, you will want to follow the steps in the Installation section on the machine where you want to run Flexicoder.  This will install the Flexicoder application into your Microsoft Dynamics GP installation and the update will be completed automatically in that process.