They first asked me "Please describe your business: what do you do, what are the products, and how you reach out to customers." After I answered, they asked me for:
Color photos of driver’s license, front and back (in PDF)
Voided check and one month of bank statement (in PDF)
Form 1099 and client invoices in 2019/2020 (in PDF)
Complete 2019 federal tax filing (in PDF)