How can I get posts in the community tab?

I want to get a list of posts in the community tab.

I tried to use the commentThreads().list() method, but without success - when I specify channelId, I get the error: The video identified by the <code><a href="/youtube/v3/docs/commentThreads/list#videoId">videoId</a></code> parameter could not be found. Even using the suggested YouTube options (channelId = "UCAuUUnT6oDeKwE6v1NGQxug"), I get this error. What should I do?