Can I get a free developer test account for Integration.

I appreciate you for sharing your concern with us, sashank. I can provide more information about this topic.

To obtain a free developer test account for integration with Salesforce and the Arka Inventory application in QuickBooks Online (QBO), you can visit the Intuit Developer website and sign up for a developer account. This will allow you to access the necessary tools and resources for integrating your application with QBO.

However, if you need to subscribe to a QuickBooks Online account, you can sign up for a 30-day trial and integrate it into other applications. Refer to the screenshot below:

I'll be right here if you need a hand on this. You can also ask questions about QuickBooks Online integration by leaving a reply to this thread.