Civilians should never salute!
When a soldier salutes what he is actually saluting is the flag/emblem on his hat/beret and not whatever is in front of them! So, if you’re not wearing a military hat what on earth could you possibly be saluting?
A soldier in civilian attire may salute with his index finger to the temple, but civilians should simply stand attention and/or place their hand across their heart when saluting the flag.
A civilian saluting militarily is nothing short of mockery to the armed forces and you’d think the president of the US would know that…