Does QBO offer am "in person" sales terminal app which integrates to our QBO?

You can apply for GoPayment credit card processing, lee-holter.

If you have QuickBooks Payments, customers can pay their invoices by credit card or ACH bank. You can click this link to sign up: Apply for GoPayment.

I also added some articles for additional reference about GoPayment in QuickBooks Online:

• Use GoPayment in the QuickBooks Online app.
• Process a credit card transaction with GoPayment.
• Understand your credit card processing statement.

I'm just a post away if you have any additional questions on this. I'll be around to keep helping.