Fcitx doesn't work with Viber in Arch Linux

My computer runs Arch Linux and I use fcitx to write my native language. I have installed fictx, fcitx-unikey, fcitx-im, fcitx-configtool, and it works well with any software I have here except Viber. It seems that Fcitx doesn't recognize Viber typing environment. So what should I do? Please help me. Thanks