※パスと転送先IPは適宜指定。
rsync -e "ssh -i /home/user/.ssh/id_ed25519" /home/user/source/file.txt remoteuser@192.168.1.100:/home/remoteuser/destination/rsync -e "ssh -i /home/user/.ssh/id_ed25519" /home/user/source/file.txt remoteuser@192.168.1.100:/home/remoteuser/destination/