FCSVR10 height - EPSG:5597

WKT

VERTCS["FCSVR10_Height", 
	VDATUM["Fehmarnbelt_Vertical_Reference_2010"], 
	PARAMETER["Vertical_Shift", 0.0], 
	PARAMETER["Direction", 1.0], 
	UNIT["Meter", 1.0]]

WKT2

VERTCRS["FCSVR10_Height", 
	VDATUM["Fehmarnbelt_Vertical_Reference_2010"], 
	CS[vertical, 1], 
	AXIS["Gravity-related height (H)", up, 
		LENGTHUNIT["Meter", 1.0]], 
	ID["EPSG", "5597"]]

Data from @esri/proj-codes

{
  "wkid": 5597,
  "latestWkid": 5597,
  "macro": "PE_VCS_FCSVR10_HT",
  "name": "FCSVR10_Height",
  "wkt": "VERTCS[\"FCSVR10_Height\",VDATUM[\"Fehmarnbelt_Vertical_Reference_2010\"],PARAMETER[\"Vertical_Shift\",0.0],PARAMETER[\"Direction\",1.0],UNIT[\"Meter\",1.0]]",
  "wkt2": "VERTCRS[\"FCSVR10_Height\",VDATUM[\"Fehmarnbelt_Vertical_Reference_2010\"],CS[vertical,1],AXIS[\"Gravity-related height (H)\",up,LENGTHUNIT[\"Meter\",1.0]],ID[\"EPSG\",\"5597\"]]",
  "description": "FCSVR10 height",
  "authority": "EPSG",
  "version": "7.9.1(10.1.1)",
  "deprecated": "no",
  "areaname": "Europe - Fehmarnbelt inner",
  "extent": {
    "slat": 54.42,
    "nlat": 54.76,
    "llon": 11.17,
    "rlon": 11.51
  }
}