mpirun error

Dear folks
I'm new to CFDEM and I'm trying to run a tutorial example of following:
"tutorials/ParScale/cfdemSolverPisoSTM/packedBedTempParScale"
however, after I type "./Allrun.sh" this error shows up:
--------------------------------------------------------------------------
mpirun has detected an attempt to run as root.
Running at root is *strongly* discouraged as any mistake (e.g., in
defining TMPDIR) or bug can result in catastrophic damage to the OS
file system, leaving your system in an unusable state.

You can override this protection by adding the --allow-run-as-root
option to your cmd line. However, we reiterate our strong advice
against doing so - please do so at your own risk.
--------------------------------------------------------------------------

what should I do? I have followed the documentation instructions.
https://www.cfdem.com/media/CFDEM/docu/CFDEMcoupling_Manual.html#tutorials