The Select from page attachments option enables you to choose any existing diagram attached to the page with the .drawio extension, insert it into the page, and open it for editing.
When you click the Attachments button, a list of page attachments with the .drawio extension will be displayed:
Selecting the diagram will open it in the editor.
When you have finished working with the diagram, click the Save & Exit button to save the changes and exit editor or Exit to discard the changes made (if any) and leave.
After that, you'll see the preview of the selected diagram.
