A question regarding Ekko and Press The Attack

This is a question on the matter of timing and how abilities are coded...

Press the attack applies a damage amp on anyone you attack 3 times. Ekko's passive does bonus damage on a 3rd hit.

Which one procs first? The damage amplification, or the damage from the third strike? In other words... is the 3rd strike damage for ekko's passive amplified by Press The Attack? Or does it only apply to all subsequent damage?

Which is it...

Option 1:

Attack, attack, attack (damage amp from Press The Attack applied) (damage from 3rd strike ekko passive comes in, amplified by press the attack)

-or-

Attack, attack, attack (damage from ekko passive) (damage amplification applied)