The new update of iTunes (iTunes 12.7) has dropped the support for the App Store.
In order to purchase e-Sword HD or e-Sword LT or any other Bible program with a PC need you to use an older version (12.6.2 or older)
Or using the App Store in iPad or iPhone.
It is still possible to upload the Apple based modules to e-Sword HD or e-Sword LT with the new version of iTunes.