Dansk Normal Nul - EPSG:5733

WKT

VERTCS["Dansk_Normal_Nul", 
	VDATUM["Dansk_Normal_Nul"], 
	PARAMETER["Vertical_Shift", 0.0], 
	PARAMETER["Direction", 1.0], 
	UNIT["Meter", 1.0]]

WKT2

VERTCRS["Dansk_Normal_Nul", 
	VDATUM["Dansk_Normal_Nul"], 
	CS[vertical, 1], 
	AXIS["Gravity-related height (H)", up, 
		LENGTHUNIT["Meter", 1.0]], 
	ID["EPSG", "5733"]]

Data from @esri/proj-codes

{
  "wkid": 5733,
  "latestWkid": 5733,
  "macro": "PE_VCS_DANSK_NORMAL_NUL",
  "name": "Dansk_Normal_Nul",
  "wkt": "VERTCS[\"Dansk_Normal_Nul\",VDATUM[\"Dansk_Normal_Nul\"],PARAMETER[\"Vertical_Shift\",0.0],PARAMETER[\"Direction\",1.0],UNIT[\"Meter\",1.0]]",
  "wkt2": "VERTCRS[\"Dansk_Normal_Nul\",VDATUM[\"Dansk_Normal_Nul\"],CS[vertical,1],AXIS[\"Gravity-related height (H)\",up,LENGTHUNIT[\"Meter\",1.0]],ID[\"EPSG\",\"5733\"]]",
  "description": "Dansk Normal Nul",
  "authority": "EPSG",
  "version": "6.7(9.3.0.0)",
  "deprecated": "no",
  "areaname": "Denmark - onshore",
  "extent": {
    "slat": 54.5,
    "nlat": 57.81,
    "llon": 7.98,
    "rlon": 15.28
  }
}