Just press the button in wpForo > Overview admin page, then find all the phrases in wpForo > Phrases admin page.

You can also use Loco Translate to translate all phrases. Don't forget to update the POT file in Loco Translate plugin.

Add some phrases, some get translate, other don't ...

If you can’t find some phrase you can add it using button.

I did the same thing than the video, search for "Followers" and "favored", but I can't find anything...

The Quick Translation - Phrases are available, see video

https://www.screencast.com/t/BdEI7fsE5

I already look in the WpForo phrases, but didn't find any phrases I want to translate.

I instal Loco Translate, and saw that French is all tranlated. So don't know where are this phrases ^^'

You can use e.g. the plugin Loco Translate
or the Quick Translation - Phrases integrated in wpForo
more information you can find here > https://wpforo.com/docs/root/translation/

I would like to know if it's possible to translate the phrase I highlight in the image or not? I try to find them in the settings of WpForo but I can't find them.

Thanks!