If you started a Rough Cut edit (in Chat & Edit mode) and you're trying to export but cannot, the issue most likely you need to complete the edit first.
Rough Cut edits are those that have a narrative arc.
In this edit type, Eddie suggests a story framework composed of 2 or more "chapters".
The chapters are shown to the left of the video player, like here:
As you can see in the above, the first chapter "Introduction & Conflict: The Fall and The Foundation" is completed and the next one has not been completed. Thus, you cannot export this story yet.
This user (in this example) would need to complete the "Resolution & Conclusion" chapter and then get to the "Final Cut". Then they can export the Final Cut story which comprises of the both chapters.
The want to get to the next chapter is to type in the prompt box and tell Eddie you're happy with this chapter and to move on to the next chapter.