Again, you don’t know the definition of fascism.

https://www.anarchistnews.org/content/it-fascism-now

Italian anarchists tried to organize a united front of the left and the unions to resist the Fascists physically, but the Socialist and Communist parties would not agree. A decade later, Leon Trotsky similarly urged the German Socialists and Communists to cooperate in combatting the Nazi Storm Troopers, with a similar lack of action by the Social Democrats and Stalinists.

Similar things happened in Spain. Either accept Democrats as allies against fascism, or enable fascism. Those are the only choices.