Hi there, js1103.
Welcome to QuickBooks Community. I'll be sharing information to ensure you can integrate Carta to QuickBooks or vice versa. Then, you'll be routed to the right person to assist you further on this matter so you can link the two software smoothly.
Based on the error you received, I suggest making sure that you already complete all the setups of your QuickBooks Online account. To do this, you can open this article to see various guidelines on how to finish the settings and tailor the program to better fit your needs: Get started with QuickBooks Online.
After that, try to connect your QuickBooks to Carta again to see if you can sync the two software without receiving any prompt messages.
If the issue continues, I'd recommend contacting the Carta Support Team. This way, they can check if their software can integrate with QBO international version. Also, they'll be able to provide steps to fix the error you're getting so you can proceed with the integration correctly.
Lastly, you may refer to this article to view various details on how you bring over your data from another software into QuickBooks using Excel: Import data from other software into QuickBooks Online.
Please know that you're always welcome to swing by if you have other questions or concerns regarding connecting a third-party app to our program. I'm always here to help. Take care and be safe, js1103.
