GDA2020 3D - EPSG:7843

WKT

GEOGCS["GDA2020_3D", 
	DATUM["GDA2020", 
		SPHEROID["GRS_1980", 6378137.0, 298.257222101]], 
	PRIMEM["Greenwich", 0.0], 
	UNIT["Degree", 0.0174532925199433], 
	LINUNIT["Meter", 1.0]]

WKT2

GEOGCRS["GDA2020_3D", 
	DYNAMIC[
		FRAMEEPOCH[2020.0], 
		MODEL["GDA2020-PMM"]], 
	DATUM["GDA2020", 
		ELLIPSOID["GRS_1980", 6378137.0, 298.257222101]], 
	PRIMEM["Greenwich", 0.0], 
	CS[ellipsoidal, 3], 
	AXIS["Latitude (lat)", north, 
		ORDER[1], 
		ANGLEUNIT["Degree", 0.0174532925199433]], 
	AXIS["Longitude (lon)", east, 
		ORDER[2], 
		ANGLEUNIT["Degree", 0.0174532925199433]], 
	AXIS["Ellipsoidal height (h)", up, 
		ORDER[3], 
		LENGTHUNIT["Meter", 1.0]], 
	ID["EPSG", "7843"]]

Data from @esri/proj-codes

{
  "wkid": 7843,
  "latestWkid": 7843,
  "macro": "PE_GCS_GDA2020_3D",
  "name": "GDA2020_3D",
  "wkt": "GEOGCS[\"GDA2020_3D\",DATUM[\"GDA2020\",SPHEROID[\"GRS_1980\",6378137.0,298.257222101]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433],LINUNIT[\"Meter\",1.0]]",
  "wkt2": "GEOGCRS[\"GDA2020_3D\",DYNAMIC[FRAMEEPOCH[2020.0],MODEL[\"GDA2020-PMM\"]],DATUM[\"GDA2020\",ELLIPSOID[\"GRS_1980\",6378137.0,298.257222101]],PRIMEM[\"Greenwich\",0.0],CS[ellipsoidal,3],AXIS[\"Latitude (lat)\",north,ORDER[1],ANGLEUNIT[\"Degree\",0.0174532925199433]],AXIS[\"Longitude (lon)\",east,ORDER[2],ANGLEUNIT[\"Degree\",0.0174532925199433]],AXIS[\"Ellipsoidal height (h)\",up,ORDER[3],LENGTHUNIT[\"Meter\",1.0]],ID[\"EPSG\",\"7843\"]]",
  "description": "GDA2020 3D",
  "authority": "EPSG",
  "version": "8.9.4(12.7.0)",
  "deprecated": "no",
  "areaname": "Australia - GDA",
  "extent": {
    "slat": -60.55,
    "nlat": -8.47,
    "llon": 93.41,
    "rlon": 173.34
  },
  "frameEpoch": 2020,
  "deformationModel": "GDA2020-PMM"
}