USA citizen received PPR...unclear how to get COPR

Hi there. We received PPR yesterday, but there are no email addresses or mailing addresses to submit the documents they are requesting. All other countries have directions via vfsglobal, but no option for USA. I know there are two USA offices (LA and NYC) but we haven’t ever sent them anything before…do we send them these documents now? Or…is it via webform? Or…do we courier mail to Canada?