Found a gramplet named prerequisites, some missing

Wow that was difficult to find, pclos is an abbreviation for PCLinuxOS, with all the issues you are having my guess is that your installation for both PCLinuxOS and Gramps was not done correctly. Also according to this review PCLinuxOS KDE 2020.05 Review: Not for the Novice you may want to try a easier Linux distribution like Ubuntu 20.04?

How did you install Gramps did you use the rpm file from PCLinuxOS or the deb file from the Gramps project download page?

Can you start a open a console or terminal and type the command:

gramps

this should start Gramps and if you can copy paste the output from the command line here (not a screenshot!) it should help us confirm if Gramps is installed correctly?