PSSCALE windows GMT5

How to use command psscale? I am using the following command via windows and the scale does not showing.

psscale -D22.8/23/4i/0.5ih -Ccont.cpt -B:continuous: -O -K >> test.ps

Could you help me?

You are plotting the color bar outside of a A4 paper (the default paper in GMT) so it’s natural that you don’t see it.

οκ so what should i do in order put put the horizontal scale in my map?

Well, give it coordinates inside the A4 paper. e.g. -D10c/5c/4i/0.5ih

The coordinates are:
-R22.6/23.8/40.38/41

how could I write my commant?

psscale in GMT5, I think, could only use paper coordinates, so I already gave you a possible solution. But you should update to GMT6 and read the manual page and look for the examples.