To open eraser settings:
When "Erase entire object" is enabled, an entire object (e.g., an entire stroke) will be erased.
When "Erase locked objects" is enabled, locked objects will become erasable.
You can also adjust the types of objects that can be erased, by default only Pen and Highlighter are erasable.
For Scribble to erase, please refer to this article for details: https://notewise.freshdesk.com/support/solutions/articles/150000169934-scribble-to-erase-handwriting