Once you start running your route in-game you can create a live session where Keystone.guru will aid you in completing your M+ key. You may follow another user's map movements by selecting the option when clicking their icon/initials in the top header.
Any participant of the live session may also select any of your existing pulls (your current pull, in-game) and then on any enemy that is not part of your route to indicate an accidental pull. Keystone.guru will then attempt to correct your route by excluding any enemies that are part of your current route that are potentially skippable without utilizing shroud/invisibility pots.
Your live session may be shared with anyone by simply copying the URL. They will be able to join once they are logged into Keystone.guru.
If your route is assigned to a team that you are a part of, any members of that team currently viewing this route will receive an invitation to your join live session.