Unable to delete tweets in Nightowl

I can't delete any tweets in Nightowl - the option to delete them is dimmed in the menu. Can anyone tell me why this might be? I'm only just really starting to use Nightowl so may be missing something obvious…?

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#1 You can only delete your own

You can only delete your own tweets. There's no need to delete other tweets coming in because the list will always get cleared when you reopen night owl.

#2 exacly you can delete your own

As Piotr mention above you can only delete your own tweets.
Hi Catherine to delete your own tweets is simple only select the tweet
and press command delete follow for the confirmation you don't have to go at apple menu.