Hello, Steven Tay,
Please follow the next steps:
1/ Go to Appearance > Widgets > add language switcher into “Right side top bar area”
2/ Go to Header Builder > add the Widget element to the header content where you want to show it, for example – https://gyazo.com/e361fd1e9329d425ba6a9f8e66771819
3/ Settings of Widget 1 > select the widget area https://prnt.sc/0jJmTkd-pDgX
We hope this has been made clear.
Kind Regards,
8theme team