Do I need a BlueX Pay account to receive a payment from a business that uses BlueX Pay?

No. You don't need a BlueX Pay account to receive money from businesses who use BlueX Pay. The business who is sending you money has created an account with BlueX Pay to make it easier for them to make international payments. But just like any bank, they can use their BlueX Pay account to send money to accounts held with other banks. Simply provide them with your usual bank details.