One page says win the same jackpot and another says we purchase your entry. Those are not the same thing to me. Before anybody pays, what exact words and documents should they check to know whether a physical US ticket exists?
Look at what the order confirmation promises. A ticket-ordering service should identify the lottery and draw, explain who buys and holds the original ticket, provide ticket proof, and state who claims each prize level. A lottery wager does not give you ownership of a state-issued ticket; the company pays according to its own betting terms if the result matches.
If the terms only say same jackpot or equivalent winnings and never explain the original ticket, treat it as a wager, not a ticket. If the terms do claim a real ticket, still check the issuing lottery's rules: Mega Millions specifically says its tickets are not sold outside the United States and that agent purchases for players in other jurisdictions are prohibited.