MacOS 10.14.6 (Mojave) / Safari 14.0.3

In Finder I can see the following section and folders in the sidebar:

iCloud

• iCloud drive
• Documents
• Desktop

However, if I open safari, go to a site where I can upload a file and look at the pop up/finder-style window, that whole 'iCloud' sidebar section is missing (but all the other folders e.g. local HD, NAS etc are visible)

How can I upload iCloud files from Safari 14 on macOS 10.14 ?