Warning
In order to build WarpX on a specific GPU cluster (e.g. Summit), look for the corresponding specific instructions, instead of those on this page.
In order to build WarpX with GPU support, make sure that you have cuda and mpich installed on your system. (Compiling with openmpi currently fails.) Then compile WarpX with the option USE_GPU=TRUE, e.g.
make -j 4 USE_GPU=TRUE