Processing customer invoices in Finland using our Payment feature is currently unavailable in QuickBooks Online UK. This is likely the reason why there’s no payment option showing after clicking the Review and Pay button.
I recommend looking for a 3rd-party software that can integrate with QBO and perform the task for you. Navigate through this site and search in the categories section to find the app that suits your business needs: Apps Center.
In the meantime, I suggest visiting our Small Business UK Blog to know more about our latest happenings. From there, you'll get the recent news, features, and updates about our products.
Let me know if you need anything else. I'm right here to help. Enjoy your day!