I dont have it in front of me right now but I think its in the second tab (online).
Second Tab most likely, Import.
Note: you still need to ensure your tvdb option is checked and there is valid mirror defined in the Online tab. The other data still needs to come from there. You dont need to worry about the account id.
Its only the the trakt ratings what we get from elsewhere.
I had a peak at the source code and its called: Automatically update community ratings and votes from trakt.tv
It should exist in the Online tab, since its not there in your screenshot I suspect you are not using the latest version which is v4.3.0
https://www.team-mediaportal.com/index.php?option=com_mtree&task=att_download&link_id=17&cf_id=24