Hello mdj101!
Thanks for finding an article about handling fixed assets in QuickBooks before posting your question. Let me help you.
You can use the Tangible assets account type since your using the QBO UK version. Then, select a Detail Type that fits for the kind of asset you're tracking. You can have this verified with an accountant.
Although the article you see is more suitable for a US account, the principles behind it are just the same. I'm sending feedback for it though.
We'll be more than happy to assist you if you have more concerns. Just reply on this thread.