POSGAR 2007 + SRVN16 height - EPSG:9521

WKT

HVCOORDSYS["POSGAR_2007_and_SRVN16_height", 
	GEOGCS["GCS_POSGAR_2007", 
		DATUM["D_POSGAR_2007", 
			SPHEROID["WGS_1984", 6378137.0, 298.257223563]], 
		PRIMEM["Greenwich", 0.0], 
		UNIT["Degree", 0.0174532925199433]], 
	VERTCS["SRVN16_height", 
		VDATUM["Sistema_de_Referencia_Vertical_Nacional_2016"], 
		PARAMETER["Vertical_Shift", 0.0], 
		PARAMETER["Direction", 1.0], 
		UNIT["Meter", 1.0]]]

WKT2

COMPOUNDCRS["POSGAR_2007_and_SRVN16_height", 
	GEOGCRS["GCS_POSGAR_2007", 
		DATUM["D_POSGAR_2007", 
			ELLIPSOID["WGS_1984", 6378137.0, 298.257223563]], 
		PRIMEM["Greenwich", 0.0], 
		CS[ellipsoidal, 2], 
		AXIS["Latitude (lat)", north, 
			ORDER[1]], 
		AXIS["Longitude (lon)", east, 
			ORDER[2]], 
		ANGLEUNIT["Degree", 0.0174532925199433]], 
	VERTCRS["SRVN16_height", 
		VDATUM["Sistema_de_Referencia_Vertical_Nacional_2016"], 
		CS[vertical, 1], 
		AXIS["Gravity-related height (H)", up, 
			LENGTHUNIT["Meter", 1.0]]], 
	ID["EPSG", "9521"]]

Data from @esri/proj-codes

{
  "wkid": 9521,
  "latestWkid": 9521,
  "pcsWkid": 0,
  "gcsWkid": 5340,
  "vcsWkid": 9255,
  "macro": "PE_HVC_POSGAR_2007_SRVN16_HEIGHT",
  "name": "POSGAR_2007_and_SRVN16_height",
  "wkt": "HVCOORDSYS[\"POSGAR_2007_and_SRVN16_height\",GEOGCS[\"GCS_POSGAR_2007\",DATUM[\"D_POSGAR_2007\",SPHEROID[\"WGS_1984\",6378137.0,298.257223563]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433]],VERTCS[\"SRVN16_height\",VDATUM[\"Sistema_de_Referencia_Vertical_Nacional_2016\"],PARAMETER[\"Vertical_Shift\",0.0],PARAMETER[\"Direction\",1.0],UNIT[\"Meter\",1.0]]]",
  "wkt2": "COMPOUNDCRS[\"POSGAR_2007_and_SRVN16_height\",GEOGCRS[\"GCS_POSGAR_2007\",DATUM[\"D_POSGAR_2007\",ELLIPSOID[\"WGS_1984\",6378137.0,298.257223563]],PRIMEM[\"Greenwich\",0.0],CS[ellipsoidal,2],AXIS[\"Latitude (lat)\",north,ORDER[1]],AXIS[\"Longitude (lon)\",east,ORDER[2]],ANGLEUNIT[\"Degree\",0.0174532925199433]],VERTCRS[\"SRVN16_height\",VDATUM[\"Sistema_de_Referencia_Vertical_Nacional_2016\"],CS[vertical,1],AXIS[\"Gravity-related height (H)\",up,LENGTHUNIT[\"Meter\",1.0]]],ID[\"EPSG\",\"9521\"]]",
  "description": "POSGAR 2007 + SRVN16 height",
  "authority": "EPSG",
  "version": "10.013(13.2.0)",
  "deprecated": "no",
  "areaname": "Argentina - onshore",
  "extent": {
    "slat": -55.11,
    "nlat": -21.78,
    "llon": -73.59,
    "rlon": -53.65
  }
}