You asked Where/how do I connect my Monzo business account in the QuickBooks app ? I can’t find it

Welcome and thanks for reaching out to the Community, @djsenior.

Adding or connecting your bank in QuickBooks Online (QBO) is pretty simple. Please refer to these steps on how:

1. Click the Hamburger icon found at the top-left section of the app.
2. Press the Banking menu then select the financial institutions connect.
3. If you're unable to see your F.I. on the list, try entering its name on the search field.

Just in case, I'll add these articles for future reference:

• Compare mobile app features.
• Mobile applications hub.

Reach out to me in the comment section below if you have any other questions or concerns. I'm more than willing to help. Have a good one!