Garuda and EndeavourOS are literally the same distro with a different default KDE theme. You can go to KDE settings, themes and search sweet candy or sweet Mars or whatever it was called and install it on EOS.
Maybe Garuda has the chaotic AUR by default I don't remember but since you're still on Arch and therefore expected to rtfm you should probably just figure out how to install it on EOS instead tbh, assuming you really want/need it