I prefer another way to achieve this goal, through joplin's attachment resources

Specifically

  1. Create a web board
  2. Support saving as .kanbandown.png, and carry some hidden custom information
  3. Support reading pictures of .kanbandown.png and reading hidden custom information
  4. Implement joplin plugin to combine Kanban and webview

But since I use GitHub Project as the board, I don’t need this feature