ASVD02 height - EPSG:6643

WKT

VERTCS["ASVD02_height", 
	VDATUM["American_Samoa_Vertical_Datum_of_2002"], 
	PARAMETER["Vertical_Shift", 0.0], 
	PARAMETER["Direction", 1.0], 
	UNIT["Meter", 1.0]]

WKT2

VERTCRS["ASVD02_height", 
	VDATUM["American_Samoa_Vertical_Datum_of_2002"], 
	CS[vertical, 1], 
	AXIS["Gravity-related height (H)", up, 
		LENGTHUNIT["Meter", 1.0]], 
	ID["EPSG", "6643"]]

Data from @esri/proj-codes

{
  "wkid": 6643,
  "latestWkid": 6643,
  "macro": "PE_VCS_ASVD02_HT",
  "name": "ASVD02_height",
  "wkt": "VERTCS[\"ASVD02_height\",VDATUM[\"American_Samoa_Vertical_Datum_of_2002\"],PARAMETER[\"Vertical_Shift\",0.0],PARAMETER[\"Direction\",1.0],UNIT[\"Meter\",1.0]]",
  "wkt2": "VERTCRS[\"ASVD02_height\",VDATUM[\"American_Samoa_Vertical_Datum_of_2002\"],CS[vertical,1],AXIS[\"Gravity-related height (H)\",up,LENGTHUNIT[\"Meter\",1.0]],ID[\"EPSG\",\"6643\"]]",
  "description": "ASVD02 height",
  "authority": "EPSG",
  "version": "8.2.10(10.3.1)",
  "deprecated": "no",
  "areaname": "American Samoa - Tutuila island",
  "extent": {
    "slat": -14.43,
    "nlat": -14.2,
    "llon": -170.88,
    "rlon": -170.51
  }
}