LUREF 3D - EPSG:9893

WKT

GEOGCS["LUREF_3D", 
	DATUM["D_Luxembourg_Reference_Frame", 
		SPHEROID["International_1924", 6378388.0, 297.0]], 
	PRIMEM["Greenwich", 0.0], 
	UNIT["Degree", 0.0174532925199433], 
	LINUNIT["Meter", 1.0]]

WKT2

GEOGCRS["LUREF_3D", 
	DATUM["D_Luxembourg_Reference_Frame", 
		ELLIPSOID["International_1924", 6378388.0, 297.0]], 
	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", "9893"]]

Data from @esri/proj-codes

{
  "wkid": 9893,
  "latestWkid": 9893,
  "macro": "PE_GCS_LUREF_3D",
  "name": "LUREF_3D",
  "wkt": "GEOGCS[\"LUREF_3D\",DATUM[\"D_Luxembourg_Reference_Frame\",SPHEROID[\"International_1924\",6378388.0,297.0]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433],LINUNIT[\"Meter\",1.0]]",
  "wkt2": "GEOGCRS[\"LUREF_3D\",DATUM[\"D_Luxembourg_Reference_Frame\",ELLIPSOID[\"International_1924\",6378388.0,297.0]],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\",\"9893\"]]",
  "description": "LUREF 3D",
  "authority": "EPSG",
  "version": "10.043(13.1.0)",
  "deprecated": "no",
  "areaname": "Luxembourg",
  "extent": {
    "slat": 49.44,
    "nlat": 50.19,
    "llon": 5.73,
    "rlon": 6.53
  }
}