https://en.m.wikipedia.org/wiki/No_true_Scotsman
Since communism has proven to be impossible to implement and every attempt has resulted in brutal authoritarian regimes, we can either say communism is an incoherent mess of a utopian ideology which can’t exist, or an ideology that de facto endorses brutal authoritarianism. Dealer’s choice
Other than not understanding how logical fallacies work, you’ve almost got it. Keep at it and I’m sure you’ll get there, eventually.
And there’s the smug arrogance
“That’s not real communism! Nothing is real communism!” Hahahahahahaha
Once you’ve read some Marx, Engels, and maybe even Lenin - you can come back here and criticize the actual ideas and arguments behind Communism rather than the completely imaginary ones you’ve blindly accepted from others.
Until then, we really have nothing more to talk about.