Ah yes sure you can do that.
If you install it as a simple package you just cd into the folder you want and run the command 'copyparty' otherwise you can simply use docker compose and set it up that way: https://jaredheinrichs.substack.com/p/how-to-setup-copyparty-using-docker
there you can just point the path of your syncthing folder into the /media directory inside the docker container