We recently switched from QuickBooks Desktop to Online and we want to unleash its full potential. Right now, we have our own software that makes the Invoice PDFs with our own data structure, lines, and branding. We are also creating Invoices using the QuickBooks API to track all of our accounting.
In the future, we want to let the users pay online with the link generated by the API when we create an invoice, however, that link includes the PDF generated by QuickBooks as the Invoice PDF. We want to know if we can customize that: whenever the client clicks on See Invoice in PDF in any instance, they see our attachment instead of the QuickBooks generated one.
Our Intuit Developer's Team will be able to help you with your API needs, Marco Vega.
You can go to the Intuit Developer website so you'll be able to ask questions from there in relation to your software. I've attached a screenshot so you'll be guided visually:
Then, make sure to create an Intuit Developer account so you can log in. Once done, you can now start exploring QuickBooks Online APIs right away through the API Explorer.
To explore more about QuickBooks Online, you can read these articles for your reference: Help Articles for QBO.
Keep in touch if you need any help from us with your software. We'll always make sure that we'll be able to address your needs and further assist you.