Hi Marco Tradify, 

Thank you for visiting the Quickbooks Community.  

API integration depends if the specific feature is supported by the plan you are subscribe. If it is, you can reach out to our Developer team to get your own API integrated with Quickbooks Online. You may refer on our website to check on plans and features that is available in each plans, click here.

Feel free to reach out to us if you have questions. 

Nona