Notion is a really great product but it's sometimes slow to open so that's an issue when you want to write just a short note or write down some quick thoughts.
To do that, you first need the Apple Shortcuts app.
1- Create a new shortcut
2 - Add an URL action and put the Notion page URL you want to access quickly
3 - Add an Open URL action that will open the URL in the Notion app
4 - Choose an icon and add the shortcut to your homescreen for quick access