If those plugins are not compiled for Linux specifically, you can’t really add them since the binaries are not compatible. Vendors would need to make them for Linux.
Having said that, if the source code to the plugin is available, you should be able to compile it yourself and get it running, unless there are some OS-specific (e.g. Windows only) dependencies.
For simple plugins it might be as easy as modifying configuration file(s) and compiling. But for more complex plugins that depend on other (external) libraries (especially if they are not as readily available for Linux, or part of UE) it is quite involving.
I’m not saying it’s not doable, only that it potentially requires a considerable time investment in porting, debugging and troubleshooting.