% date; apt-cache search --names-only "bijiben|knotes" | popsort.py Fri 23 Jul 2021 10:38:08 AM EDT 6285 bijiben - intuitive note editor integrated with GNOME 3 3474 knotes - sticky notes application
Open the note -> right click on the title bar -> Preferences -> Editor Settings -> Rich text
Right click on the application icon -> Configure KNotes -> Editor -> Rich text -> OK
Note: