FSFPAY_API_USERNAME=your_username
FSFPAY_API_KEY=your_api_key
FSFPAY_SECRET_KEY=your_secret_key
FSFPAY_API_URL=https://panel.fsfpay.com/api/v1/create_payment    # example
FSFPAY_IFRAME_URL=https://panel.fsfpay.com/pay/iframe            # sample iframe base
