Implement Document protect / unprotected in Word Office.js Api

I'm developing an add-in using Word's JavaScript API and need to restrict changes by locking with a password
I also need to unlock, and therefore make editable, some areas of the document

This seems like a very basic function that is needed and is missing.

https://support.microsoft.com/en-us/office/allow-changes-to-parts-of-a-protected-document-187ed01c-8795-43e1-9fd0-c9fca419dadf

Thanks