Timbalai 1948 - EPSG:4298

WKT

GEOGCS["GCS_Timbalai_1948", 
	DATUM["D_Timbalai_1948", 
		SPHEROID["Everest_Definition_1967", 6377298.556, 300.8017]], 
	PRIMEM["Greenwich", 0.0], 
	UNIT["Degree", 0.0174532925199433]]

WKT2

GEOGCRS["GCS_Timbalai_1948", 
	DATUM["D_Timbalai_1948", 
		ELLIPSOID["Everest_Definition_1967", 6377298.556, 300.8017]], 
	PRIMEM["Greenwich", 0.0], 
	CS[ellipsoidal, 2], 
	AXIS["Latitude (lat)", north, 
		ORDER[1]], 
	AXIS["Longitude (lon)", east, 
		ORDER[2]], 
	ANGLEUNIT["Degree", 0.0174532925199433], 
	ID["EPSG", "4298"]]

Data from @esri/proj-codes

{
  "wkid": 4298,
  "latestWkid": 4298,
  "macro": "PE_GCS_TIMBALAI_1948",
  "name": "GCS_Timbalai_1948",
  "wkt": "GEOGCS[\"GCS_Timbalai_1948\",DATUM[\"D_Timbalai_1948\",SPHEROID[\"Everest_Definition_1967\",6377298.556,300.8017]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433]]",
  "wkt2": "GEOGCRS[\"GCS_Timbalai_1948\",DATUM[\"D_Timbalai_1948\",ELLIPSOID[\"Everest_Definition_1967\",6377298.556,300.8017]],PRIMEM[\"Greenwich\",0.0],CS[ellipsoidal,2],AXIS[\"Latitude (lat)\",north,ORDER[1]],AXIS[\"Longitude (lon)\",east,ORDER[2]],ANGLEUNIT[\"Degree\",0.0174532925199433],ID[\"EPSG\",\"4298\"]]",
  "description": "Timbalai 1948",
  "authority": "EPSG",
  "version": "6.5(3.0.1)",
  "deprecated": "no",
  "areaname": "Asia - Brunei and East Malaysia",
  "extent": {
    "slat": 0.85,
    "nlat": 7.67,
    "llon": 109.31,
    "rlon": 119.61
  }
}