Captions are set on the AVID

timeline and you'd like to export

Place the timeline indicator on a caption in the timeline

Make sure that the Video Track is Selected

The choices you will have are .stl or .txt

Then you'll have to convert the .stl to a .srt

Use this tool but instead of choosing .stl choose .srt

How to convert a .stl to a .srt file that will import in Adobe Premiere or Resolve as Closed or Open Captions

How to convert a .srt to a .stl file that will import in AVID Media Composer as Closed or Open Captions