Following that article, I see that in order to “import data from a previous Brave profile” I need to use “the dropdown menu of detected browsers,” so I go back up to the previous section, “How do I import from another browser?” in order to find out about said drop-down menu.
Steps there are:
1. Launch Brave and open the Main menu: 
Done.
2. Select Bookmarks > Import Bookmarks and Settings
Done.
3. Select from the list of detected browsers you want to Import from
There is no such list. I get a dialogue box, titled “import bookmarks and settings,” with an unlabeled drop-down that contains only one option: “Bookmarks HTML File,” under which is a heading “Select items to import:” with a single check-box labeled “Favorites/Bookmarks.”
At this point, I wonder what I should do, as the instructions very specifically direct me to “ensure that the Bookmarks option is NOT checked.” This seems to be the only option, and I see no browsers detected, Brave or otherwise.
4. Check the desired settings to import and click Import
I’m still on step #3, but the only option I have is to cancel or to “Choose File.”