How to generate force field parameter for KOH & NaOH for OPLS force field

since lipargen does not work for NaOH & KOH, how should I make its input file.

You should make the effort to explain clearly what you want to achieve using rigorous, scientific language. What is “its input file”?
I can only recommend you reading section 8.6.4 from the latest LAMMPS Manual, explaining how to create a complete input deck (i.e. a data file and LAMMPS input script) for an organic solvent using Moltemplate and the OPLS-AA force field.

There is no “lipargen” in the LAMMPS distribution. So please explain its relation to LAMMPS.
Please also explain what it is exactly that you want to do. Nobody here is a mind reader and can complete the minimal information that you are providing.