Hello Jackcowdrey,
You can input these coordinates here :
Option/Project Préférences/Location Settings
To understand how it works :
https://helpcenter.graphisoft.com/user-guide/127874/
IFC BIM model include geodesic coordinates.
To export these geodesic coordinates into an IFC model you have to check your IFC translator before.
Christophe - FRANCEArchicad Designer and Teacher
Archicad 15 to 27 FRA FULL
OS 11.6 Big Sur - MacBook Pro 2017 - 16Go RAM
"Quality is never an accident ; it's always the result of an intelligent effort" John Ruskin