uBlock Origin settings

Can’t set some settings declaratively in Librewolf. “selectedFilterLists” is fine, but “userSettings” stays default. I’m doing the same according to Firefox NixOS wiki page and to uBlock Origin json syntax, I think. What am I doing wrong? extensions = { force = true; settings = { "uBlock0@raymondhill.net".settings = { userSettings = rec { # not working too userSettings = { uiTheme = "dark"; }; selectedFilterLists = [ "JPN-1" ]; }; }; }