I have recently been facing certain problems such as the QuickBooks Invoice Online Checkout integrated into my website, https://pythononlinecompiler.com/.

The idea is to let users make payments right from the QuickBooks, which has its own secure payment gateway.

There have been some problems during the integration and test phases of this functionality that I would like to point out and discuss.

Problem 1: Inconsistent Order Processing

One of the issues is with inconsistent payment processing. All transactions generally go through but sometimes get an error message back. It is not consistently failing, so it has been hard to diagnose. The error logs seem to point toward a timeout problem, but the details of the cause are still vague.

Has anyone else had this problem with QuickBooks Online Checkout and, if yes, how did you resolve it?

Another issue can be related to delay in confirmation of payment.
After having made any payment, it waits for some time before the confirmation reaches them and gets updated into the system.

This is rather frustrating because users, indeed, expect an instant response after completing a transaction. I've checked the API settings, and everything seems fine, yet the delay persists. QuickBooks might be misbehaving here, or should I go back and look into some server-related issue?

Issue 3: Python-based Applications Integration

Since my site, https://pythononlinecompiler.com/, is based on Python, there have been some in-house codes required to integrate QuickBooks Invoice Online Checkout.

I followed the official QuickBooks API documentation but still have compatibility issues. In particular, the SDK for QuickBooks Online does not actually support the Python-based application, and there are many unexpected bugs and errors during integration.

Therefore, I am looking for someone who has already integrated QuickBooks Online Checkout with any Python applications and may recommend libraries or provide some workarounds.

I am now seeking advice from the developer community on insights and possible solutions to these challenges.

QuickBooks is a beautiful tool, but these problems greatly weight down on the seamless user experience that I aim to provide on https://pythononlinecompiler.com/.

Any advice, resources, or sharing of experiences on how to fix these issues and make this checkout process better for my users would be greatly appreciated.

Also, if you have suggestions on other payment gateways that can integrate well with Python-based applications, do let me know. I'm going with QuickBooks for the accounting module, so I could use an alternative to QuickBooks for online payment processing if it provides a great user experience.

Thanks in advance for your replies and suggestions!