Have a quarter of a million illegal votes already been found in the Arizona audit?

An exact release date of results from the audit is not known, but no results had been released by April 26, 2021, when a social media post claimed a quarter million illegal votes had been found.

The audit, commissioned by Republicans in the state Senate, is of ballots from the 2020 general election in Maricopa County, Arizona's most populous county.

In a statement dated March 31, 2021, state Senate Republicans said a report would be issued "in about 60 days." 

Doug Logan, head of the private company leading the audit, said that he expects the counting of ballots to take 16 days. The audit began on April 23, 2021.

In other words, it's not clear when the results of the audit will be released. But it is clear that no results had been announced at the time the social media post was made.