Trapalanda does not exist in EU4: it can only exist if it is imported from CK2 using the CK2-EU4 converter. It would be the only nation with an animal culture except for Jan Mayen.
Playing Trapalanda in EU4 requires the following:
- Crusader Kings II
- CKII: Sunset Invasion (with the setting Aztec Invasion activated)
- EU4 Save Converter
There is no way to form Trapalanda directly in Europa Universalis IV.
Crusader Kings II Import
One can export a saved game from Crusader Kings II and import it into Europa Universalis IV with the EU4 Save Converter DLC. To import Trapalanda into an EU4 game, Sunset Invasion must be actived and the option will generate a completely new American continent, with a huge spanning Aztec Empire against a superpower Inca Empire, while Trapalanda is created, as an easter egg, owning Falkland Islands.