lyx files with spaces or other special characters in the path or file name may not work with this approach on some Windows systems) SumatraPDF -reuse-instance -inverse-search "CMD /C (ECHO LYXCMD:revdvi:server-goto-file-row:%f %l) > \\.\pipe\lyxpipe.in" Set the Viewer field to Custom with a command.Tools → Preferences → File Handling → File Formats
Open Zathura config file, usually in home directory ~/.config/zathura/zathurarc.Tools→Preferences→Output→General→PDF command: zathura -synctex-forward $$n:1:$$t $$o (don't miss space before $$o).