Power of Attorney Attestation in SFO Embassy

Hi,
Can you please let me know what are the documents required to get POA attestation from SFO embassy, i have POA got drafted from India for bank loan and I am on H1b. is 2 witness signatures mandatory to get attestation or we can send documents without Apostille POA(just notarized POA) and 2 witness signatures?

Thanks,
Sathish