GDAL project lat lon coordinates to UTM in C

Question

I have dug up some old code I wrote 6 years ago that was doing the conversion from Lat Lon coordinates to UTM.

I have tried to run it today and the code returns NaN values. I suspect there has been some significant changes with GDAL. I am using GDAL 3.0 on Arch Linux.

Function latlon2utm takes X1, Y1 lat/lon coordinates and returns UTM coordinates X2, Y2

#include "ogr_api.h"
#include "ogr_srs_api.h"

void LatLon2UTM(double *X1, double *Y1, double *X2, double *Y2)
  {
  int zone;
  int err;

  printf("%f %f\n", *X1, *Y1);
  OGRGeometryH pt1;
  OGRSpatialReferenceH SREF;
  OGRSpatialReferenceH UTM;

  SREF = OSRNewSpatialReference(NULL);
  OSRImportFromEPSG(SREF, 4326);

  zone = (int)(((*X1 + 180.0) / 6.0) + 1.0);
  UTM = OSRNewSpatialReference(NULL);
  if(*Y1 < 0) OSRSetUTM(UTM,zone,FALSE);
  if(*Y1 > 0) OSRSetUTM(UTM,zone,TRUE);

  pt1 = OGR_G_CreateGeometry(wkbPoint);

  //printf("%f %f", *X1, *X2);
  OGR_G_SetPoint_2D(pt1, 0, *X1, *Y1);

  OGR_G_AssignSpatialReference(pt1, SREF);

  // Convert to UTM
  err = OGR_G_TransformTo(pt1,UTM);
  printf("%d", err);

  *X2 = OGR_G_GetX(pt1, 0);
  *Y2 = OGR_G_GetY(pt1, 0);
  printf("%f %f\n", *X2, *Y2);
  }

Is There anyone that could give me the proper way to do that?