[zaikunzhang]

This is the case for only the NAG Fortran compiler (nagfor).

All the other major Fortran compilers on the market are easily available in the "modern" way: gfortran, Intel ifort/ifx, NVIDIA nvfortran, Classic flang, AOCC flang, and Arm flang. All of them are available on Ubuntu with .deb packages. For the last two, you need to download the .deb files manually, but the others can be installed via apt. In addition, they are all free of charge, although this is less important point.