I am a CS student who is currently creating a lightweight integration between canvas and notion. The use case isn't quite the same, my integration appends assignments, announcements, and quiz / exam dates as entries in a database, which are then propagated throughout the Page.
During discovery I have found 2 ways of authenticating myself programmatically. OAuth and API tokens. As chriscas1 pointed out, DO NOT share any tokens you generate. My integration aims to be a "on machine" application that a user would download, configure tokens, and RUN ON THEIR MACHINE. This way the only person receiving your tokens is yourself. Once I figure out how to implement OAuth for user authentication, you (might) not need to generate tokens. Will let you know if this hobby project ever yields a vi