You’re overcomplicating it. Wix doesn’t natively let you require document uploads during member sign-up with verification. You have two realistic paths:
Use Wix Forms + Manual Approval
Create a form that asks for KBIS upload.
Require manual review before granting member access.
Hide member-only content until you approve.
Use a third-party app
Something like 123FormBuilder, JotForm, or Zapier to handle file upload + automated notifications.
Connect it to Wix so the file goes somewhere secure and triggers your review.
Trying to do automated KBIS verification is not feasible inside Wix. You’ll always need a manual check.