Source: The New York Times - Link
A member of the far-right nationalist Proud Boys was in communication with a person associated with the White House in the days just before the Jan. 6 assault on the Capitol, according to a law enforcement official briefed on the investigation.
Location, cellular and call record data revealed a call tying a Proud Boys member to the Trump White House, the official said. The F.B.I. has not determined what they discussed, and the official would not reveal the names of either party.
Doesn’t sound much like antifa to me.