Does Quickbooks Online support an external IdP such as Okta ? And does it support SP initiated SSO ?

It's nice to see you here today, @James11_2. Let me route you to the support team that can guide you with your concerns.

There's a community dedicated to developers and integrating other websites with QuickBooks. I recommend that you sign up and post this question to our separate online forum called Intuit Developer Community.

This site contains resources for software development, as well as the ability to ask fellow developers questions. Our Intuit Developer can provide you with further details on how to develop or integrate paying contractors with a direct deposit via API.

 Here's how:

1. Go to this link: https://help.developer.intuit.com/s/.
2. Choose QuickBooks Online under What do you need help with? 
3. Click Ask a Question. 
4. Log into your existing Intuit Developer Account or create a new one. 
5. Enter your concern. 
6. Click Ask. 

Additionally, you can always utilize the API Docs & Tools and Blog menu on the Intuit Developer's page. From there, you can check out the latest feature added to the application.

Please post again or leave a comment on this thread should you have any additional questions about integrations or concerns with QuickBooks. I'm always here to answer them. Take good care!