H4 Biometric appointment location - US mailing address or US Physical address

Hello,
My question is regarding the H4 Biometrics appointment location?
The appointment centre is given based on US mailing address or US physical address ?
form i539 and instructions does not specify how they choose the location, it just say your local USCIS centre so I am assuming it may be based on the US Physical address ?

Answer is available on Biometric appointment page.