Hello Bob,
Welcome to the community and thanks for turning to the right place for seeking help.
There is this GitHub repo that has those fonts: GitHub - BannedPatriot/ttf-wps-fonts: Symbol fonts required by wps-office.
You can manually download those .ttf files. The ttf files are basically the font files. Once you have the required TTF files, you can install the fonts by double clicking on them
Once you have installed all those missing fonts on your system, you won’t see the pop-up message.