Mike from Zerto here. There are two different VPG exports:
In the VPGs tab of the ZVM or ZSSP GUI, there is an EXPORT link that will create a CSV file that contains the settings of all current VPGs for use as reference
In the Zerto Diagnostics Tool on the ZVM VM, there is an Export VPG Settings option that generates an XML file that can be used for importing VPGs that have been deleted