I can't use "Path Cursor" with "Add Tween"

Hello, I can’t use “Path Cursor” together with “Add Tween”. Version 1.19. What should I do?

Maybe double click the object that your tweening, it will open a clip and you can edit object in their.

When you double-click, dots appear, but it does not allow you to edit.

Oh I meant the the object that is being tween, if it doesn’t show a blue/green box around the object then you can’t enter the object clip.