WebHelp, new localization file

[Yuriy_1977]

Hi!
I need to add a new localization file to scenario "DITA Map WebHelp Responsive".
So:
1. I add the attribute xml:lang with value "ru" in my ditamap file;
2. Create the file "srings-ru.xml" with my strings in ...frameworks\dita\DITA-OT3.x\plugins\com.oxygenxml.webhelp.responsive\oxygen-webhelp\resources\localization;
3. Add the line <lang xml:lang="ru" filename="strings-ru.xml"/> in the file "srings-ru.xml".
But it doesn't work I am getting many errors like
[DOTX052W]: No string named 'jump.to.content' was found when creating generated text; using the value 'jump.to.content' in your output file.
Need some advice on how to make the new localization work.
I use css for customization.
Thanks in advance.

[Yuriy_1977]

Hi!
I found how to do it in your documentation.
This article helped me - https://www.oxygenxml.com/doc/versions/ ... responsive. Section "Adding a New Language".