The "Trump gives his salary to the government" thing is, on some level, a scam. He either doesnt do so or the quarterly performances where they say he gave it to this agency or that one is a lie. Why? Because no agency or department of the government can accept gifts of money...

...they announce every quarter, he has given the money to the VA, or the Small Business Administration, or the Department of Homeland Security, but *every one of those* would be breaking the law if they accepted the money. The best they can do is immediately forward it to...

...the federal treasury. But if that was what was happening, why would they keep doing the quarterly performances of announcing what agency is getting his money? Either the performance is a lie or, more likely, he isn't giving a dime.

https://www.gao.gov/htext/d06382sp.html