qtranslate x in the header

Hi @thuyishere
You can use one of the methods described in the qTranslate-X FAQ https://qtranslatexteam.wordpress.com/faq/#LanguageSwitchingMethods namely add menu item to the header menu.

If the menu item isn’t an option for you, you can use widget or create a shortcode yourself, for example as described at https://gist.github.com/corellian/1086856a90570e2ac44146ed81f144ee (this code is not mine and I can’t confirm whether it’s still working or not).

Hi thank you for your help. I did not notice your answer until recently.
I have a question. My theme doesnt have header widget, so how can I get the translation bar on the header?

@thuyishere
can you give a link to your site in question and the theme you use?

Try opening the WP Customizer panel, navigating to the “Menus” section and assigning some menu to the header (“top menu”) and adding LanguageSwitcher to that menu.