Finding official physical "paper" sheet music for "Happiness by the Kilowatt" (by Alexisonfire or City and Colour) is difficult because it was primarily released as digital scores or custom transcriptions rather than a mass-marketed physical book.
Happiness By The Kilowatt (City And Colour) - Piano tutorial happiness by the kilowatt piano sheet musiciso 2021
If you are still searching for a 2021-style transcription, here are the three tiers of difficulty: Finding official physical "paper" sheet music for "Happiness
Because specific "2021 Edition" sheet music books for this specific song are rare (it usually appears in "The Purity of Pines" era collections or Greatest Hits compilations), most players encounter transcriptions by fans or MuseScore exports. Legitimate options as of today:
Legitimate options as of today: