Be careful of the scammers at Amsterdam Centraal. They may also appear at other big stations. They often start by asking "Do you speak English?" and then they ask you to buy train tickets for them. They pretend they are from Ukraine going to Germany.
Another story: He pretends he is going to Germany but his Google Pay is not working at the NS ticket machine. (The fake app shows a green tick but NS machine has no response) He ask you to withdraw cash for him, and he will transfer the money back via a (fake) bank app.
Another story: He pretends he is going to Germany but his Google Pay is not working at the NS ticket machine. (The fake app shows a green tick but NS machine has no response) He ask you to withdraw cash for him, and he will transfer the money back via a (fake) bank app.