Search for a file named draft_content.json in your CapCut Projects folder. The default location is:

On Windows:
C:\Users\user\AppData\Local\CapCut\User Data\Projects\com.lveditor.draft\

On MacOS the file is called draft_info.json and is located in:
/Users/user/Movies/CapCut/User Data/Projects/com.lveditor.draft