Do not worry if you do not have an extruded folder. If you do not, the command prompt will automatically create one for you.
Of course, change the XX to the width of a single tile in the image & YY to the height of a single tile in the image. If you have NO margin OR spacing, remove the --margin parameter & --spacing parameters ENTIRELY. If your tileset DOES have a margin & / or spacing, specify that margin number in place of YY & that spacing number in place of ZZ.
Last but not least, in your code, say for example your tiles are 64x64, because you extruded your tileset, they now become 66x66 because extrusion adds 1 margin & 2 spacing.
If you extrude correctly, you should see absolutely 0 seams.