To add your macro to the insert menu, select macro dialog, and macro placeholder, you'll need the following:
A brand icon to be used by the web items in the insert menu and the macro browser. For best results, provide a square image that's at least 80x80 pixels.
Optionally, you can provide an image placeholder to represent what the content will look like in the editor (if you don't provide one, your brand icon is shown)
How do users add your macro?
Users can insert your macro in the editor by either:
Using the insert button in the toolbar
Pasting a link or URL (auto convert)
UI components
Your macro listed in the insert menu
The macro browser: You'll need a short text description for your macro
The macro placeholder in the editor
The macro editor
The macro properties panel
Auto converting a URL
Recommendations
Write a concise paragraph that describes your app.
If possible, use a flat visual style for your icon.
Use a placeholder image to show a sample preview of your app. It helps users understand what the content will look like when they switch from editing the page to viewing it.