Steps for a new drawing:

• Open editor: https://www.draw.io/
• If you are asked to select storage click Decide later,
• Create new drawing,
• Click File Save as..., enter a name, click GitHub,
• Select this repo in Select Folder window, hints:
  • you can change branch by clicking branch name in the path on the top,
  • it is not possible to create a new branch or a directory in this window, so it have to be done on github before openning the Save as... window.
• Click File Embed IFrame
• Customize Width and Height if needed,
• Select Lightbox and Edit
• In Edit box change to Custom... and confirm default URL
• Click Create and copy HTML code
• Paste code to destination

Embeded drawing is visible to everyone, but edit is only possible for this repo collaborators. If you have no access ask me for it.

WARNING!!!

GitHub cache policy is causing long time to update already embeded image after changing it. It may take up to 5 minutes.

• Insert more content (plus icon)
• Other macros...
• Find and select
  

  HTML
  Allows the use of HTML code within a Confluence page.

• Click Insert
• Paste HTML code to new HTML frame

Editing drawing will automatically update image on confluence page, it may take up to 5 minutes. Refreshing page is required.