It is not reading what you write
Type anything at all — the words are thrown away. What gets measured is the gaps between your keystrokes: how fast, how even, how long you stop, how often you go back.
0 keystrokes — 40 needed
The numbers are real — they are your actual keystroke intervals, measured in this page and sent nowhere. The reading is a joke. Typing rhythm genuinely is distinctive enough to identify people by, which is a real field called keystroke dynamics, but nobody has ever shown it says anything about your character, and this page is not the first to manage it.