MBOX is not available on any top U.S. cryptocurrency exchanges. It can be traded on Pancake Swap, which is a decentralized exchange (DEX), and non-U.S. customers can buy it on Binance.
This isn't necessarily a red flag -- many coins are difficult to buy in the U.S. But newer investors may not be comfortable buying from a DEX, as it can be more complicated and carry different risks than a centralized exchange