He did.
While it’s true that President Donald Trump has donated most of his salary to different federal agencies throughout his term, he still profits off of real estate and other business dealings. It would be false to say he works for “no money.”
He has charged secret service, politicians, world diplomats, and even charities he’s hosted at his properties to make back if not more than he would’ve earned.
Not to mention the millions he’s made from merchandising and illegally taken from political donations and contributions which are still under investigation, litigation, etc.
Further, Trump could not forgo all his payments as President due to legal reasons and was required to take at least $1 year. And while the first three and half years of his quarterly salary was documented and donated, the last two quarters remain unknown.
https://www.usatoday.com/story/news/factcheck/2020/07/11/fact-check-donald-trump-donates-salary-but-he-still-makes-money/5410134002/