Hi,
We are looking to create a crypto payment gateway where client that wants to purchase a product can choose to deposit cryptocurrency.
Client will be presented with a unique address+qr code and amount to deposit.
When funds arrive an event will be sent to our backend.

The project is for the backend logic only, nodejs.
We would like to support ETH,BTC, USDT(ERC20) , USDT(TRC-20), LTC

Presented budget is $5 just to post,
Kindly let us know cost and time frame for this development