Sorry I don't believe a president should have to release his tax information unless it is integral to discovery in a court of law.
His privacy doesn't end at the moment he declares for the office. He's still a citizen with the same protections we all have.
President Trump is not a lifelong politician like the previous losers. They all had time to start “Foundations” and stuff as a way to hide their bribes. That way they could produce a very bland tax return that reveals nothing.