Can we delete the active Invoices using Quickbooks api? Whenever I cancel the Policy, It should delete the invoice in quickbooks online. Is this possible through api?

You can use this app. You can create a trigger and the action is to find a specific invoice and delete it.

https://www.make.com/en/register?pc=quickbooks

We may not be able to confirm the feasibility of your request regarding APIs in the Community, @saideepika. However, we can direct you to the Intuit Developer page, where APIs and other third-party application issues are answered. 

Our Community includes engineers, developers, QuickBooks users, and other third-party application users who could share their experiences and provide insights about your concerns.

1. Go to this link: https://help.developer.intuit.com/s/.
2. Select QuickBooks Online and click the Ask a Question button.
3. Provide the necessary information about your concern as you did on the Community page. 
4. Click Ask.

They will jump into your post and provide the necessary details that will help you get through the scenario.

Please keep us informed about any updates regarding your questions in QBO, leave a comment below. I'll be happy to assist you. Have a great day!