Alhamdulillah(all praise to god), after three sleepless days I finally can use cups to print my work.
I use Epson stylus C90 printer. Due to C90, cups does not provide the driver, so I use the driver for c68 (I know that after I asked in the forum slackware Indonesia).
But remember, do not use the cups as root because the printer does not work well
(I hope you can understand my words