Before building a script, you must understand the basics of Codex profiles. You can find all the information about Codex and the profiles here.
Sending a .txt file for translation doesn't require any specific parameters. Simply generate a new TXT script inside your Codex repository and leave all its parameters empty:
selectionPathList =  contextsPath =  groupingPaths =  contentNames =  groupingPathNames =  targetInjections =  targetInjectionsRange =