Your DMM will handle up to 10A of DC current to 600V, place the selector switch in the 10A position. If you move the black probe to the top left connector indicated by the diagonal line it will run through the meter and will be fused. You can try this and see if it works, you will likely only blow the fuse if the draw is more than 10A. You would break your positive input and run it through the DMM so that it is in series with the load, in this case the router. Depending upon the flow of current it will read - or positive. If your Black lead is connected to the PS + terminal and red lead to the motor + input, it should indicate positive current. If it reads negative, reverse the leads. If the fuse blows, you can replace the fuse and we can go to the next incremental step for measuring current.
A DC shunt is another alternative to measure current on a circuit in excess of your equipment. I can expound upon this later if required.
You can also venture into loggers with multiple channels, but I don’t think we need to go there.