As a SaaS provider, I want to integrate my client's invoice data from SAP into our application

Hi,

I hope I am in the right place. I am a SaaS application product owner that allows companies to manage their patents. We get several requests from some clients who are also SAP clients to integrate their SAP account into our tool in order to get the invoice data through an API.

Our need is to get the invoice data into our application. Is there a specific API we can integrate? Is there a special place to do this? Documentation?

Thanks a lot in advance for your help,

Baptiste