When I install dnscrypt-proxy, I found no dnscrypt-proxy.service here.
I write a bash to launch it, and write a desktop file here, ~/.config/autostart/dnscrypt.desktop
#!/bin/bash
zenity --password --title="sudo"|tr -d '\n'|sudo -S dnscrypt-proxy -R cisco -a 127.0.0.2:53 -u `whoami`
But it no work after input password. I can not found gksudo and gnome-keyring-query in the repo, so I use zenity.