john carter

You can utilize the OAuth 2.0 Authorization Code Grant flow. This involves manually obtaining an initial refresh token using a tool like Postman with user interaction, and then programmatically refreshing the token in your Windows service without the need for user interaction. Ensure the necessary permissions are granted to your application, and securely manage the obtained refresh token. This approach allows for seamless authentication in a non-interactive environment like a Windows service application.

To record daily sales, you can consider using payment processing APIs such as Stripe or Square, both of which offer comprehensive solutions for handling both "Cash Payment" and "Card Payment" transactions. These APIs provide functionalities for recording and managing sales transactions, supporting a variety of payment methods. You can integrate their services into your system to seamlessly record daily sales, streamline payment processing, and gain access to relevant transaction data. Assess your specific requirements and features offered by these APIs to determine which best suits your needs for recording daily sales.