According to your website:

Shop everywhere Mastercard cards are accepted, including: eBay, Airbnb, Walmart, Etsy, Amazon, Doordash, Facebook, PayPal.

Can you prove and guarantee that the card will work on all these sites without problems?
Can I customize the card with a specific name? Or does it come ready-made with other usernames.
Not asking for identity verification is against the financial system. What will you do if Visa or MasterCard discovers that you are issuing cards without identity verification?
Will you refund the money if the cards do not work in the above sites?
What is your policy with data? privacy?