Update singularity-it4i.md

docs.it4i/software/tools/singularity-it4i.md

-!!!warning
-    This page has not been updated yet. The page does not reflect the transition from PBS to Slurm.
-
 # Apptainer on IT4Innovations
 
 !!!note "Singularity name change"
@@ -137,7 +134,10 @@ New version is ready. (/home/username/.apptainer/images/CentOS-7_20230116143612.
 ### MPI
 
 In the following example, we are using a job submitted by the command:
-`qsub -A PROJECT -q qprod -l select=2:mpiprocs=128 -l walltime=00:30:00 -I`
+
+```bash
+$ salloc -A PROJECT_ID -p qcpu --nodes=2 --ntasks-per-node=128 --time=00:30:00
+```
 
 !!! note
     We have seen no major performance impact for a job running in a Apptainer container.