2 part print. Print the front facing down and the back facing up. It's already in this orientation in the 3mf file. There is a 4mm hole located in the back plate for the cord.
My cords are 4mm so that's what i've always went by but in your slicer just right click the back plate and choose add negative part, choose the cylinder and place it on the plate over the existing hole and enlarge to your desired size and slice.