LAS07 height - EPSG:9666

WKT

VERTCS["LAS07_height", 
	VDATUM["Lithuanian_Height_System_2007"], 
	PARAMETER["Vertical_Shift", 0.0], 
	PARAMETER["Direction", 1.0], 
	UNIT["Meter", 1.0]]

WKT2

VERTCRS["LAS07_height", 
	VDATUM["Lithuanian_Height_System_2007"], 
	CS[vertical, 1], 
	AXIS["Gravity-related height (H)", up, 
		LENGTHUNIT["Meter", 1.0]], 
	ID["EPSG", "9666"]]

Data from @esri/proj-codes

{
  "wkid": 9666,
  "latestWkid": 9666,
  "macro": "PE_VCS_LAS07_HT",
  "name": "LAS07_height",
  "wkt": "VERTCS[\"LAS07_height\",VDATUM[\"Lithuanian_Height_System_2007\"],PARAMETER[\"Vertical_Shift\",0.0],PARAMETER[\"Direction\",1.0],UNIT[\"Meter\",1.0]]",
  "wkt2": "VERTCRS[\"LAS07_height\",VDATUM[\"Lithuanian_Height_System_2007\"],CS[vertical,1],AXIS[\"Gravity-related height (H)\",up,LENGTHUNIT[\"Meter\",1.0]],ID[\"EPSG\",\"9666\"]]",
  "description": "LAS07 height",
  "authority": "EPSG",
  "version": "10.013(12.9.0)",
  "deprecated": "no",
  "areaname": "Lithuania - onshore",
  "extent": {
    "slat": 53.89,
    "nlat": 56.45,
    "llon": 20.86,
    "rlon": 26.82
  }
}