Thanks for posting in the Community, @vmhconsulting77.
I've searched the HoneyBook from our QuickBooks App Center, and I got no results for this. Thus, I'd suggest contacting their dedicated support team to confirm if your clients can sync their HoneyBook account with QuickBooks Online (QBO). They can also verify if the invoicing and payments will come easy to manage from there.
Additionally, I recommend going to the Client apps tab from the Apps menu. You can add, launch, rate, support, or disconnect an app from there, such as HoneyBook. The screenshot below serves as your visual guide. For more details, see this article's Client apps section: How To Manage Apps In QuickBooks Online Accountant (QBOA).
I'll lend a helping hand if you need anything else. Take care always, @vmhconsulting77.