For people that might be confused about why this is important, it's due to a nuance of American law. In the US, with few exceptions, you cannot be compelled to testify against yourself under the fifth amendment. That includes providing something you know like a PIN or password. However, you can be compelled to provide biometrics, and it is not uncommon for American police to forcibly unlock your phone with your face or other biometrics for nonconsensual searches, even without a court order. This is a real risk for Americans encountering an increasingly authoritarian government, including at protests, police checkpoints, border crossings, military occupations of US cities, and ICE raids.

If you aren't a US citizen or resident, then it's possible that this information doesn't apply to you.