Qestion how can I sync with hard-drive and SD card on 1 PC

im on a linux ubuntu 20.4, and I want to sync the files on my hard-drive with my SD card for other things like my offline gamecube that cant go on my network. in lets say /Retroarch/saves with /media/littlemac/OBESE/retroarch/savefiles all on one PC. how can i get it to just sync every time I put my SD card in my PC with syncthing running. and I all so sync this file with my android over the network, idk if that matters just info i guess.

“Out of the box”, Syncthing can not sync folders on the same machine. If is designed for network operation only. But if you are willing and able to run two instances of Synching it can be done.