Tell me. What's their first response to any judge making a ruling they don't like, or any journalist writing an article they don't like. What is their opinion of the other political parties or situations where parliament doesn't go along with what (they claim) ''the people'' want.
Far right party after far right party always has the same response to these matters. That only they truly represent the people and that thus no other party except them does, that any judge who stands in their way is an enemy or a fake judge, and that any journalist that reports on their statements or misdeed is scum. Checks and balances so important to democracies is something they always oppose, and they seem to drift to the stance that any other party except them is illegitimate.
So that's the anti democratic part down.
As for authoritarianism. Well, being against free press and judicial oversight already strikes me as plenty authoritarian. And look what happens whenever they get into power. The press always gets chained up, judges get replaced by cronies and checks and balances get removed, with some far right governments going so far as to just jail or have their opposition murdered. Look at Russia, at Hungary, at Turkey and the others. Also they're all fervent admirers of how Putin strangled Russian democracy, with some Austrian demagogue nutcase even getting caught on camera bragging about how he wanted to have his party do the same in Austria.