What does this mean: The changes made to invoice needs an internal approval before it can be sent to customer?

You'll receive the internal approval message once a common task and reminders are set up or configured on the Workflow automation page. I'll guide you on how to sort this out, Brenda. 

When setting up a task, you can find it under My Workflows tab on the Workflow automation page. I've added screenshots for your reference guide: 
 

This setup provides convenience for account administrators by enhancing security and restricting entries in QuickBooks, which ensures the accuracy of your financial records. This is the reason why you're getting the error: 
 

When you click the "Submit for Approval" button, you'll notify the approver or validator about this transaction. Using workflows, you can automate routine tasks and notifications such as invoice reviews, payment collections, and transaction approvals. You define the criteria for when reminders should be sent and to whom.

However, if you don't want this message to appear, you'll want to reach out to your Primary Administrator and inform to disable the feature. Just toggle it to off to disable it. 

Please know that you'll have to approve all open invoices before your can disable this workflow. 

The screenshot provided maybe from the US region but it functions similarly in the Canada version.

To give you more details on how to set up the workflow, I've added this for you: Use workflows to automate your business processes for QuickBooks Online Advanced.

Additionally, learn how you to record invoice payments with QuickBooks Online: Record Invoice Payments.

If you have any questions or other concerns when creating invoices and workflows, let me know. I'm always right here willing to assist you further. Have a nice day!

We don't want approvals or payments!

We didn't request this, and the message about needing approvals just showed up in QBO on his iPad on Friday night.

He cannot send/email invoices to his clients/customers now.

We need to turn this off! He is a sole proprietor of our business, he does not need any other internal approval. He creates an invoice, and send it to the customer from QBO.

I understand the impact of this auto-approval on your workflow and overall experience with QuickBooks Online (QBO), Brenda.

Please note that when using the Workflow automation feature, QBO will automatically ask for approval before you can send/email your invoices.

Since the auto-approval option isn't necessary for your business, please follow my colleague's instructions above and make sure to toggle off the approval feature.

I'm sharing this resource for additional information about workflow: Use workflows to automate your business processes for QuickBooks Online Advanced.

In addition, you can gently remind your customer about unpaid balances: Create and send customer statements in QuickBooks Online.

Feel free to add details below for further assistance with managing invoices. We're always here to help you.