What Look said. Some localities, like where I am in Florida, not allowed to run condensate into sanitary sewer. However, in other areas (NJ) we run the condensate line into a trap that will not dry, like the laundry. If there is a pan under the unit, again, as look said, we run these drains (because they should never actually run) to a visible location. We also put a float switch in the pan that will shut down the unit if that pan fills(the secondary drain fails).
Main condensate line should have a trap. I really like these:
https://a.co/d/c1rC9CT Visible with clear trap, has ports to pour in cleaning fluid(vinegar) and easy to clean.
