How to solve avanti's coin toss?

The best way for two generations to throw gold coins is to stick the two sides of two gold coins together and throw them up. After falling, they must all face up. The original title was: There was a rich man who was very stingy and often cheated money. Two generations want to teach him a lesson. One day, two generations of love went to the rich man's house and borrowed 65,438,000 gold coins from him. The rich man knew that if he didn't give it to them, Erqing would find another way to punish him, so he said to Erqing: You can lend it to him, but on one condition, if you take the gold coins out of the bag, do you know how Erqing does it? (Method tip: In order to make the gold coin face up after landing, it can only be that both sides of the gold coin face up. How can we do that? ).