SHGD2015 + SHVD2015 height - EPSG:9517

WKT

HVCOORDSYS["SHGD2015_and_SHVD2015_height", 
	GEOGCS["SHGD2015", 
		DATUM["St_Helena_Geodetic_Datum_2015", 
			SPHEROID["GRS_1980", 6378137.0, 298.257222101]], 
		PRIMEM["Greenwich", 0.0], 
		UNIT["Degree", 0.0174532925199433]], 
	VERTCS["SHVD2015_height", 
		VDATUM["St_Helena_Vertical_Datum_2015"], 
		PARAMETER["Vertical_Shift", 0.0], 
		PARAMETER["Direction", 1.0], 
		UNIT["Meter", 1.0]]]

WKT2

COMPOUNDCRS["SHGD2015_and_SHVD2015_height", 
	GEOGCRS["SHGD2015", 
		DATUM["St_Helena_Geodetic_Datum_2015", 
			ELLIPSOID["GRS_1980", 6378137.0, 298.257222101]], 
		PRIMEM["Greenwich", 0.0], 
		CS[ellipsoidal, 2], 
		AXIS["Latitude (lat)", north, 
			ORDER[1]], 
		AXIS["Longitude (lon)", east, 
			ORDER[2]], 
		ANGLEUNIT["Degree", 0.0174532925199433]], 
	VERTCRS["SHVD2015_height", 
		VDATUM["St_Helena_Vertical_Datum_2015"], 
		CS[vertical, 1], 
		AXIS["Gravity-related height (H)", up, 
			LENGTHUNIT["Meter", 1.0]]], 
	ID["EPSG", "9517"]]

Data from @esri/proj-codes

{
  "wkid": 9517,
  "latestWkid": 9517,
  "pcsWkid": 0,
  "gcsWkid": 7886,
  "vcsWkid": 7890,
  "macro": "PE_HVC_SHGD2015_SHVD2015_HEIGHT",
  "name": "SHGD2015_and_SHVD2015_height",
  "wkt": "HVCOORDSYS[\"SHGD2015_and_SHVD2015_height\",GEOGCS[\"SHGD2015\",DATUM[\"St_Helena_Geodetic_Datum_2015\",SPHEROID[\"GRS_1980\",6378137.0,298.257222101]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433]],VERTCS[\"SHVD2015_height\",VDATUM[\"St_Helena_Vertical_Datum_2015\"],PARAMETER[\"Vertical_Shift\",0.0],PARAMETER[\"Direction\",1.0],UNIT[\"Meter\",1.0]]]",
  "wkt2": "COMPOUNDCRS[\"SHGD2015_and_SHVD2015_height\",GEOGCRS[\"SHGD2015\",DATUM[\"St_Helena_Geodetic_Datum_2015\",ELLIPSOID[\"GRS_1980\",6378137.0,298.257222101]],PRIMEM[\"Greenwich\",0.0],CS[ellipsoidal,2],AXIS[\"Latitude (lat)\",north,ORDER[1]],AXIS[\"Longitude (lon)\",east,ORDER[2]],ANGLEUNIT[\"Degree\",0.0174532925199433]],VERTCRS[\"SHVD2015_height\",VDATUM[\"St_Helena_Vertical_Datum_2015\"],CS[vertical,1],AXIS[\"Gravity-related height (H)\",up,LENGTHUNIT[\"Meter\",1.0]]],ID[\"EPSG\",\"9517\"]]",
  "description": "SHGD2015 + SHVD2015 height",
  "authority": "EPSG",
  "version": "10.013(13.2.0)",
  "deprecated": "no",
  "areaname": "St Helena - St Helena Island",
  "extent": {
    "slat": -16.08,
    "nlat": -15.85,
    "llon": -5.85,
    "rlon": -5.59
  }
}