I don't have much GPU experience myself. As the sibling comment said, there are Fortran compilers that can offload to GPU, there is also Cuda Fortran. There is OpenMP offloading. I think LLVM can also target it somehow, and I would like to support it in LFortran, a compiler that we are developing. In general I am hoping people more experienced with GPU would be interested in helping out.
https://www.intel.com/content/www/us/en/developer/tools/onea...