You can manage your drafts by doing the following:

  • Tap on your profile icon in the navigation bar to get to your Profile Screen
  • Tap on the Drafts tab
  • Tap on the 3 dots at the top right of the screen
  • Tap "Manage Drafts"
  • Select the draft(s) you want to delete
  • Tap "Delete"
  • Tap the back arrow
  • You're done

Attached is a screen recording: