Welcome back to the QuickBooks Community, kevin-kevinspelm. I'll be sharing details on how a third-party integration works in QuickBooks Online. Let me also route you to the right team to assist you further.
Since Acuity scheduling is a third-party app that is connected to QuickBooks Online, the data downloaded comes from their end. With this, I suggest contacting the Acuity Scheduling Support Team because they have the tools to pull up your account in a secure environment. They can provide detailed information on how their process works as well as how to generate invoice numbers automatically when importing jobs. They can also access your account to assist you with the procedure.
Lastly, I'm also adding this article if you need further guidelines on how to effectively handle your business using QBO: Help guides for QuickBooks Online.
It'll always be my pleasure to help if you have any other concerns related to QuickBooks. Please let me know by clicking the Reply button and leaving a comment below. Take care always, kevin-kevinspelm.