Thanks for reaching out to the Community, Bhavinfds.

We have a separate forum for Intuit Developers where you can find engineers who can help suggest a third-party app and program integration in QuickBooks Online. 

Let me route you to their website: Intuit Developers Community.

You can also check this article on customising your sales forms in QBO for an additional guide: Customise invoices, estimates, and sales receipts in QuickBooks Online.

You can visit us if you need help again in the future. We're always here to help.