The ability to be sent to their mats from across the room is a handy skill for a dog to have! Once they’ve developed attraction for their mat, and are seeking it out, sending them to their mat is fairly easy to add.
Start a couple of steps back from your mat, and use a hand gesture to suggest they move forward and continue to their mat. I think about bowling (I am not a very good bowler, so my form may look different from yours) my dog to the mat. If they move past your outstretched fingers and go to their mat, click and rush forward to deliver treats on the mat.
Little by little, you can increase the distance you are asking your dog to travel to their mat!