liff.i18n.setLang() has not worked

[bathtimefish]

🐛 Bug Report

I tryed to use liff.i18n.setLang() in a project which generated by created-liff-app but it has not worked.

💁 Possible Solution

I found old version of @line/liff v2.19.1 in package.json and changed it to v2.21.3. So my code worked fine.

I guess it's a better what the latest @line/liff shoud be installed when generated the project by create-liff-app.

thanks.