QE could run in 4 parallel processors using the commando "mpirun -np 4". However, you should have mpi libraries installed on your machine (or supercomputer). If that is not the case, you should delete these words from Burai settings. In addition, Burai software should be able to find "pw.x" binary in your machine, and you should be sure that the right installation QE path was set in Burai settings.