RGM23 (lon-lat) - EPSG:10673

WKT

GEOGCS["RGM23_(lon-lat)", 
	DATUM["Mayotte_Geodetic_Reference_Frame_2023", 
		SPHEROID["GRS_1980", 6378137.0, 298.257222101]], 
	PRIMEM["Greenwich", 0.0], 
	UNIT["Degree", 0.0174532925199433]]

WKT2

GEOGCRS["RGM23_(lon-lat)", 
	DATUM["Mayotte_Geodetic_Reference_Frame_2023", 
		ELLIPSOID["GRS_1980", 6378137.0, 298.257222101]], 
	PRIMEM["Greenwich", 0.0], 
	CS[ellipsoidal, 2], 
	AXIS["Longitude (lon)", east, 
		ORDER[1]], 
	AXIS["Latitude (lat)", north, 
		ORDER[2]], 
	ANGLEUNIT["Degree", 0.0174532925199433], 
	ID["EPSG", "10673"]]

Data from @esri/proj-codes

{
  "wkid": 10673,
  "latestWkid": 10673,
  "macro": "PE_GCS_RGM23_LON_LAT",
  "name": "RGM23_(lon-lat)",
  "wkt": "GEOGCS[\"RGM23_(lon-lat)\",DATUM[\"Mayotte_Geodetic_Reference_Frame_2023\",SPHEROID[\"GRS_1980\",6378137.0,298.257222101]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433]]",
  "wkt2": "GEOGCRS[\"RGM23_(lon-lat)\",DATUM[\"Mayotte_Geodetic_Reference_Frame_2023\",ELLIPSOID[\"GRS_1980\",6378137.0,298.257222101]],PRIMEM[\"Greenwich\",0.0],CS[ellipsoidal,2],AXIS[\"Longitude (lon)\",east,ORDER[1]],AXIS[\"Latitude (lat)\",north,ORDER[2]],ANGLEUNIT[\"Degree\",0.0174532925199433],ID[\"EPSG\",\"10673\"]]",
  "description": "RGM23 (lon-lat)",
  "authority": "EPSG",
  "version": "11.021(13.5.0)",
  "deprecated": "no",
  "areaname": "Mayotte",
  "extent": {
    "slat": -14.49,
    "nlat": -11.33,
    "llon": 43.68,
    "rlon": 46.7
  }
}