Moose How to spawn ground units in a zone and after dead then spawn at next zone?

[_UnknownCheater_]

I have set a template named "Ground-1",and 2 trigger zones in ME named "zone1",''zone2'.My codes below.

GroundUnits = SPAWN:New("Ground-1")
  :InitAIOn()
  :OnSpawnGroup(
   function(SpawnGroup)
     SpawnGroup:HandleEvent(EVENTS.Dead)
     function SpawnGroup:OnEventDead(EventData)
        GroundUnits = SPAWN:New("Ground-1")
        :SpawnFromCoordinate(ZONE:FindByName("zone2"):GetCoordinate())
     end
   end
   )
  :SpawnFromCoordinate(ZONE:FindByName("zone1"):GetCoordinate())

Ang got errors:

2022-05-19 07:03:18.536 INFO    SCRIPTING: stack traceback:
    [string "C:\Users\ADMINI~1\AppData\Local\Temp\DCS.openbeta\/~mis00004C9A.lua"]:11197: in function <[string "C:\Users\ADMINI~1\AppData\Local\Temp\DCS.openbeta\/~mis00004C9A.lua"]:11194>
    [string "C:\Users\ADMINI~1\AppData\Local\Temp\DCS.openbeta\/~mis0000104B.lua"]:9: in function <[string "C:\Users\ADMINI~1\AppData\Local\Temp\DCS.openbeta\/~mis0000104B.lua"]:6>
    (tail call): ?
    [C]: in function 'xpcall'
    [string "C:\Users\ADMINI~1\AppData\Local\Temp\DCS.openbeta\/~mis00004C9A.lua"]:11538: in function 'onEvent'
    [string "Scripts/World/EventHandlers.lua"]:13: in function <[string "Scripts/World/EventHandlers.lua"]:11>