Did Donald Trump request nuclear codes for a civilization-ending strike against Iran?

Source of claim is not one who can be easily dismissed.

President Donald Trump was said by a former CIA analyst to have requested a nuclear code during a heated exchange in a White House meeting with top national security aides on the night of Saturday, April 18.

The original source of this report, Larry Johnson, appeared on an April 20 podcast hosted by former Fox News legal analyst Judge Andrew Napolitano. You can watch the video below in which Johnson made the claim (fast forward to the 4:35 mark).