The ExternalPotential analysis object only gives you the potentials due to device electrodes and electrostatic gates: http://docs.quantumwise.com/manuals/Types/ExternalPotential/ExternalPotential.html#externalpotential-c (http://docs.quantumwise.com/manuals/Types/ExternalPotential/ExternalPotential.html#externalpotential-c). There is currently no way to obtain the potential due to pseudopotentials as an analysis object. However, if you really want "a peak into" the pseudopotential, try the following. It is a developer feature:
pp=NormConservingPseudoPotential("normconserving/sg15/gga/01_H.upf")
pp.load()
pp._plot()