First thing would to find exactly which wheel is producing the noise.
After that, jack up the car and spin the wheel and see if the sound can be reproduced.
Then remove the wheel and spin the rotor and see if the sound still continues.
Depending on the outcome will pinpoint the cause.
If the noise is present with the wheel on but not with it removed, chances are pretty good something is making contact with the wheel.
If the noise is still present with the wheel removed, there is some issue with the assembly of the brakes / caliper / caliper bracket.
One other thing to note …
It may also not be an issue with the brakes but perhaps a faulty bearing or axle.
But you need to make sure of one before the other.