Can I use extra attack as the bonus action to improved war magic to get 2 hits and a spell?

Question

The War Magic feature of the Eldritch Knight states (PHB p. 75):

when you use your action to cast a cantrip [or at level 18+ a spell], you can make one weapon attack as a bonus action.

I'm quite confused: if I take that bonus action will the extra attack apply to it?

Answer 1

No.

Extra attacks can only be made as part of the Attack action. If you are taking an attack granted by something else, extra attacks do not apply.