Read the request precisely
A provider may need to establish that a payment instrument belongs to the account holder, but that does not justify sending every detail on a card. Confirm the requesting entity and the purpose of the check through an authenticated channel. Ask exactly which information is required and which details must be masked. Never invent a document or change ownership information to make a payment appear to meet a rule.
Use a secure, limited submission
Follow the verified provider's current instructions and keep a record of what was supplied. Avoid exposing security codes, passwords or one-time authentication codes, and do not post card images in a general conversation. FYLU has not published a card-verification procedure or approved document-upload route. Its automated helper cannot validate ownership, and the current preview should not receive payment credentials or unredacted evidence in anticipation of a future service.