Update Notion Databases from a Google Sheet (with Apps Script)

Phew — after two days of trying to find a solution for how to accomplish a popular, reasonable set of tasks in Notion’s API, I wanted to do my duties as a Google Developer Expert and blog the solution for others to use.

Notion databases are like Google Sheets from another dimension. On the upside, they are very pretty and loaded with the project-management features that folks have shoehorned into Sheets for years like status dropdowns. On the downside, they are very static and not as on the grid for the dynamic data sources…