ATF (Paris) - EPSG:4901

WKT

GEOGCS["GCS_ATF_Paris", 
	DATUM["D_ATF", 
		SPHEROID["Plessis_1817", 6376523.0, 308.64]], 
	PRIMEM["Paris_RGS", 2.337208333333333], 
	UNIT["Grad", 0.01570796326794897]]

WKT2

GEOGCRS["GCS_ATF_Paris", 
	DATUM["D_ATF", 
		ELLIPSOID["Plessis_1817", 6376523.0, 308.64]], 
	PRIMEM["Paris_RGS", 2.337208333333333, 
		ANGLEUNIT["Degree", 0.0174532925199433]], 
	CS[ellipsoidal, 2], 
	AXIS["Latitude (lat)", north, 
		ORDER[1]], 
	AXIS["Longitude (lon)", east, 
		ORDER[2]], 
	ANGLEUNIT["Grad", 0.01570796326794897], 
	ID["EPSG", "4901"]]

Data from @esri/proj-codes

{
  "wkid": 4901,
  "latestWkid": 4901,
  "macro": "PE_GCS_ATF_PARIS",
  "name": "GCS_ATF_Paris",
  "wkt": "GEOGCS[\"GCS_ATF_Paris\",DATUM[\"D_ATF\",SPHEROID[\"Plessis_1817\",6376523.0,308.64]],PRIMEM[\"Paris_RGS\",2.337208333333333],UNIT[\"Grad\",0.01570796326794897]]",
  "wkt2": "GEOGCRS[\"GCS_ATF_Paris\",DATUM[\"D_ATF\",ELLIPSOID[\"Plessis_1817\",6376523.0,308.64]],PRIMEM[\"Paris_RGS\",2.337208333333333,ANGLEUNIT[\"Degree\",0.0174532925199433]],CS[ellipsoidal,2],AXIS[\"Latitude (lat)\",north,ORDER[1]],AXIS[\"Longitude (lon)\",east,ORDER[2]],ANGLEUNIT[\"Grad\",0.01570796326794897],ID[\"EPSG\",\"4901\"]]",
  "description": "ATF (Paris)",
  "authority": "EPSG",
  "version": "4.5(3.0.1)",
  "deprecated": "no",
  "areaname": "France - mainland onshore",
  "extent": {
    "slat": 42.33,
    "nlat": 51.14,
    "llon": -4.87,
    "rlon": 8.23
  }
}