Tahaa SAU 2001 - EPSG:5606

WKT

VERTCS["Tahaa_SAU_2001", 
	VDATUM["Tahaa_SAU_2001"], 
	PARAMETER["Vertical_Shift", 0.0], 
	PARAMETER["Direction", 1.0], 
	UNIT["Meter", 1.0]]

WKT2

VERTCRS["Tahaa_SAU_2001", 
	VDATUM["Tahaa_SAU_2001"], 
	CS[vertical, 1], 
	AXIS["Gravity-related height (H)", up, 
		LENGTHUNIT["Meter", 1.0]], 
	ID["EPSG", "5606"]]

Data from @esri/proj-codes

{
  "wkid": 5606,
  "latestWkid": 5606,
  "macro": "PE_VCS_TAHAA_SAU_2001",
  "name": "Tahaa_SAU_2001",
  "wkt": "VERTCS[\"Tahaa_SAU_2001\",VDATUM[\"Tahaa_SAU_2001\"],PARAMETER[\"Vertical_Shift\",0.0],PARAMETER[\"Direction\",1.0],UNIT[\"Meter\",1.0]]",
  "wkt2": "VERTCRS[\"Tahaa_SAU_2001\",VDATUM[\"Tahaa_SAU_2001\"],CS[vertical,1],AXIS[\"Gravity-related height (H)\",up,LENGTHUNIT[\"Meter\",1.0]],ID[\"EPSG\",\"5606\"]]",
  "description": "Tahaa SAU 2001",
  "authority": "EPSG",
  "version": "6.15(9.3.0.0)",
  "deprecated": "no",
  "areaname": "French Polynesia - Society Islands - Tahaa",
  "extent": {
    "slat": -16.72,
    "nlat": -16.5,
    "llon": -151.63,
    "rlon": -151.36
  }
}