Miro is the only one I know of that you can embed in Notion. You could use something like MindNode and export it as an image or pdf and embed that into Notion
Unfortunately no, Notion has yet to implement passcode security. You can use the page lock setting to turn off editing ability on a page but that doesn't have a passcode
The Productive Engineer Oh that’s sad ... the whole purpose of journaling anything personal is lost without privacy .. strange that the developers of the app haven’t looked into it yet .. hopefully we get that soon. Thanks for the prompt reply :)