On screen Virtual keyboard is not visible even-though it physically present on screen and I can press key transparent panel

I am trying to use on screen keyboard in centos 7 desktop application.
I have set QT_IM_MODULE=qtvirtualkeyboard
I have created simple application which has login screen.
on focus of userid field keyboard is not visible but when I try to click on screen below userid it presses key even though keyboard is not visible.