Crypto Payment Gateway

We need a simple application to facilitate payments in BTC, BNB, ETH, USDC, USDT for the purchase of a BEP20 Token on the BSC at a fixed/set USD (US$) price. The Payment Gateway must receive payment and transfer tokens from a BEP20 wallet to the purchaser's BEP20 wallet address. The purchaser must be able to enter an alpha numeric referral code. The transaction history must be emailed to a fixed email address. Finally we would like to change the US$ price of the token occasionally - either through changing the code or through a config file. The application must be web3.