I’m also looking for help with ideal tire pressure for Schwann trailway 28” tire. It also says

Max load 80 kg at Rec Pressure 350 kPa
:
Min Pressure 40 PSI
Max Pressure 73 PSI

I weigh 190 lbs

i tried to determine optimal PSI with the info provide by Dabac but not sure I come to right number. I currently have PSI at 60 PSI. It seems fine but not entirely sure if this is the correct recommended PSI

Thanks in advance