pathfinder 2e – How does Channel Smite work?

At level 4, Berric the cleric takes Channel Smite. He then attacks someone, expending a Harm spell. From the text:

Make a melee Strike and add the spell’s damage to the Strike’s damage.

Does this mean that the basic Fortitude save mentioned in the text for Harm simply isn’t used? If Berric used a first level spell slot, which of the two possibilities below is the case when he strikes and hits?

  1. He strikes, dealing his normal weapon damage and then simply adding another 1d8.
  2. He strikes, dealing his normal weapon damage. The enemy takes 1d8 damage, but rolls a basic Fortitude save: it takes none of that 1d8 damage on a critical success, half damage on a success, full damage on a failure and double damage on a critical failure.

I think it’s the first, because the text for Channel Smite doesn’t mention any saving throw, but I’d just like to confirm…