@daveman1010220: Sorry about the file link, I have fixed it now Thank you for notifying.
I have just registered to vote up your answer and say thanks for it.
It works excellent for me, God bless you!
Because I do not like to add adhoc packages, I've tested using this recepie.
Add Bionic Beaver Repository (18.04 LTS)
# add-apt-repository 'deb http://archive.ubuntu.com/ubuntu bionic main universe'
Install Missing package
# apt install -t bionic libwebkitgtk-1.0-0
Tested with sucess with PS Client 9.1R4 in a clean installation of Ubuntu 20.04