Back in FM 14 I hired someone to build a way to push invoices to QBO.
He built a link
Sent that link to his server
His server then build the API and push it to QBO.
This works just fine, but it does require that his server be involved.
Starting with FM 16 you can build the API directly in FM.
I would like to have him rebuild for FM API, but I am curious for opinions. Everything is working fine so I hesitate to change it, but I have never been comfortable with the reliance on his server.