I’m…confused. By “the person is complaining about rigged elections being fake news,” do you mean the journalist who challenged Trump on his claim? The specific exchange as indicated in the article was:

The pair then moved onto discussing that riot, and Trump was challenged after he repeated his unsubstantiated claim that the 2020 election was rigged.

Trump turned to the California primary elections, where votes are still being counted to determine which two candidates in a series of races - including governor of the state - will be on the ballot in November’s midterm elections.

He said the results had not been called after four days, adding: “They’re cheating on the election.”

“Do you have evidence to support that?” Welker responded.

“All I have to do is look, and I listen,” the president replied.

“But that’s not evidence,” she interjected.

I wouldn’t call that complaining about the entire idea of rigged elections being fake news, but rather challenging Trump to provide evidence for his own claims of specific elections being rigged, which he insulted the journalist and then ended the interview over instead of defending his claims with evidence.