Chose one of the following methods, depending on your needs:
Copy as Text
Copy with statuses (it keeps checked/unchecked status):
Select the editor content with your mouse or Ctrl+A (Cmd+A on macOS),
Copy the content to the clipboard with Ctrl+C (Cmd+C on macOS).
Copy without statuses (all copied items are unchecked)
Copy as YAML
Use Copy as YAML menu option.
Paste as Text
Use the Paste menu option.