Synogolgy install

I am following this guide https://docs.zerotier.com/devices/synology/#set-up-container but at the point it says install docker I have the docker package installed already via the package manager so that ok right? So I moved on to Make Docker container called zt and at that point I am stumped does the code under this need to be copied and pasted into terminal (Mac) and then it works as I not sure what todo at his point.