Transcription files are saved automatically and stay available even after you close Premiere Assistant or restart Premiere. You don't need to transcribe again.
When you open [Trim], [Captions], or [Multi-cam switch] and click the transcribe button, Premiere Assistant checks whether a previous transcript exists. If one does, a dialog appears: "There is a transcript you were working on."
Select [Open previous transcript] and click [Next] to reload your previous transcript.
Caution: Selecting [Transcribe again] and clicking [Next] will overwrite your previous transcript. This cannot be undone.
Also, if you edited your Premiere timeline after applying captions through Premiere Assistant, reopening the transcript may cause sync issues.
Troubleshooting
Unsaved or unexpected shutdown
If the project was closed without saving, subtitle edits may not have been stored.
Recovery is unlikely in this case.
Check Premiere auto-saves
Premiere may have auto-saved versions of your project.
Try locating and opening one to recover your work.
Accidentally clicked Apply to Sequence?
Use the [Time Machine] button at the top-left of the Premiere Assistant menu bar to revert.
Caution: Once you use Time Machine, there is no way to undo it and return to the state before the revert.