Trump's father made money, not Trump himself. Trump has consistently lost money, not made it. I forget how many times he has put a firm of his into bankruptcy to get out of paying its debts: four or five, I think.
And once his father wasn't alive to bail him out any more, he borrowed from banks and not paid them back until there wasn't an American bank that would lend him money, and then he borrowed from Deutschebank and didn't pay them back until they wouldn't lend him any more.
Which is why he is now in hock to Russian oligarchs, who lent him money he hasn't paid back but that's ok because they are getting their money'sworth in "favours".