First, it would help if you know approximately when the hand was played. Set a date filter on the Preferences tab to get the date range that the hand falls into. Then Go to the Game Notes tab, click the Get All button, then use the Find at the top after entering the Game #.
What if i don't know the date? I have ran an export and it returned alot of errors like that one "Unable to get hand history for game #1531797607", so i would like to know which hands are those.
If the export process tells you those errors then that means the hand history text is not available for you to export. The only reason I said to use a date filter is to limit the amount of hands coming back when you click the Get All button. You don't want it to bring back millions of hands or you could run into out-of-memory problems.