Hi there, I have few question to understand the issue of your QuickBooks Integration?
1. Do you have a custom API on your OpenCart Store to connect with QuickBooks?
2. Is there any limit to fetch the number of order from OpenCart Store from QuickBooks?
3. Do you have any clue that issue is in Desktop Application or on your OpenCart Store?
If possible share me some more details so I can figure out the issue.
I am highly experience OpenCart developer and i am sure will fix your issue.
I am flexible in prices, as quality & long-term relationship is more important.
Look forward to hearing from you.
Thank you,
Hasan