Trump is a fascist and wants to be a dictator, that's true. Fascism is also not exclusive to Trump in the Republican Party. The Heritage Foundation and Project 2025 are core to the GOP, not just Trump.
Criticizing Biden/Harris for conceding to right-wing lies like on immigration or for wanting to integrate Republicans into her Cabinet are completely valid criticisms. She should be attacking them on every fascist policy they advocate for and countering them with progressive policies that are popular
Has she said who she would appoint? The only time I ever saw anything about this she was asked "would you consider putting Republicans in your cabinet?" And she said she would. Will she, possibly/probably. That said it is a twist of her words to say that she will.
Me saying "I would" consider a date with Carrie Underwood, doesn't mean I will go on one.
When she is willingly taking money from fascist governments and boasting that she is receiving endorsements from war criminals and people that Democrats themselves labeled as fascist, they are fascist.