Alas
@bui3 it's not a misprint. These are not the 20" BMX ramp tires we knew as kids. For comps, the Schwalbe 20 x1.35 ebike tires have a suggested fill of 65-95psi. Use your operational judgement based on the conditions of where you live and ride. I do run mine on the very soft side slightly below suggested guidance.
Note: running too soft, one does risk getting the classic "snakebite" pinch flat if hitting sharp curbs, potholes/sewer indents, roots, or chunky gravel. The higher the psi, the lower the rolling resistance, higher the range, longer the life on the tire, but also harsher the road feel.
For me, I would probably run closer to 75-80psi if my Dolphin had a front air suspension fork to absorb the shocks...I've looked into those options, but haven't pulled the trigger yet on anything as yet - all either
too cheap/heavy (alum/steel),
for kids, or
crazy expensive ($600-860 for one fork), or also
crazy expensive ($870).