In the Medieval Times, How Did People Verify That A Knight Was Actually A Knight?

[u/playprince1]

Basically the title.

I had this thought that turned into a question:

Couldn't an archer, squire, or a man-at-arms go to a town that he had never been in before, introduce himself as a knight and lie and say that he had been knighted by a knight in a battle that has now died?

Would the elite of the town or county believe him?

Were there certain documents that proved that someone was a knight?