If you want to spawn the Wyvern at the wyvernspawner of the map Olympus, use this lines to enable this.
Attention: You can only add one "add command" for a specific spawner!

Open the Game.ini of your server config.

Add the following lines:
[/script/shootergame.shootergamemode] # This line too is you this line isn't in your Game.ini
ConfigAddNPCSpawnEntriesContainer=(NPCSpawnEntriesContainerClassString="DinoSpawnEntriesOlympus_Wyvern_C",NPCSpawnEntries=((AnEntryName="SpecialAndCorruptedFireWyvernSpawner",EntryWeight=0.33,NPCsToSpawnStrings=("SpecialFireWyvern_Character_BP_C")),(AnEntryName="CorruptedFireWyvernSpawner",EntryWeight=0.33,NPCsToSpawnStrings=("CorruptedFireWyvern_Character_BP_C"))),NPCSpawnLimits=((NPCClassString="SpecialFireWyvern_Character_BP_C",MaxPercentageOfDesiredNumToAllow=0.02),(NPCClassString="CorruptedFireWyvern_Character_BP_C",MaxPercentageOfDesiredNumToAllow=0.02)))


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If you want to add all three versions of wyvern add:

ConfigAddNPCSpawnEntriesContainer=(NPCSpawnEntriesContainerClassString="DinoSpawnEntriesOlympus_Wyvern_C",NPCSpawnEntries=((AnEntryName="SpecialAndCorruptedFireWyvernSpawner",EntryWeight=0.33,NPCsToSpawnStrings=("SpecialFireWyvern_Character_BP_C")),(AnEntryName="CorruptedFireWyvernSpawner",EntryWeight=0.33,NPCsToSpawnStrings=("CorruptedFireWyvern_Character_BP_C")),(AnEntryName="TheDodoWyvernSpawner",EntryWeight=0.33,NPCsToSpawnStrings=("TheDodoWyvern_Character_BP_C"))),NPCSpawnLimits=((NPCClassString="SpecialFireWyvern_Character_BP_C",MaxPercentageOfDesiredNumToAllow=0.02),(NPCClassString="CorruptedFireWyvern_Character_BP_C",MaxPercentageOfDesiredNumToAllow=0.02),(NPCClassString="TheDodoWyvern_Character_BP_C",MaxPercentageOfDesiredNumToAllow=0.005)))


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If you want to add only the dodowyvern:

For DodoWyvern spawn:
ConfigAddNPCSpawnEntriesContainer=(NPCSpawnEntriesContainerClassString="DinoSpawnEntriesOlympus_Wyvern_C",NPCSpawnEntries=( (AnEntryName="TheDodoWyvernSpawner",EntryWeight=0.33,NPCsToSpawnStrings=("TheDodoWyvern_Character_BP_C"))), NPCSpawnLimits=( (NPCClassString="TheDodoWyvern_Character_BP_C",MaxPercentageOfDesiredNumToAllow=0.01) ) )


You need after this to do a destroywildlife to start the spawn.

* All DinoSpawnEntries of all Maps end with _C but you don't see this in your data explorer:
Example: The Wyvernspawner of Olympus called DinoSpawnEntriesOlympus_Wyvern but you speak to the spawner with DinoSpawnEntriesOlympus_Wyvern_C

I hope it will help :-)