I don’t believe you can be compelled to provide a password. That does after all (at the very least) constitute speech. And freedom of speech is also freedom of non-speech, they can’t make you say something.
They will however try to make you do that… In many situations authorities are allowed to lie to you. So that’s sucks. They can tell you that you’re required to unlock your phone, you just have to know that your not actually.
Also they can’t make you say anything, but they can make you do things, like for instance “put your finger here” or “look into this camera”, which is why biometric unlock is unsafe around cops.