My spine hurts every night achievement: how to get it in Die of Death

"Blue caramel fills my mind with peace." See the requirement, reward, evidence status and practical checks.

Direct answer

"Blue caramel fills my mind with peace."

Category: secret

Library category: secret.
Recorded requirement: In a private server, play Killdroid on Happy Home with the timer disabled and cooldowns off. Use Flight or Propel to reach the roof, enter the chimney without touching its inner sides, follow the backrooms-like route to the NPC, and finish the dialogue.
Recorded reward: No listed reward.
Unlock quote: "Thank you."

In a private server, play Killdroid on Happy Home with the timer disabled and cooldowns off. Use Flight or Propel to reach the roof, enter the chimney without touching its inner sides, follow the backrooms-like route to the NPC, and finish the dialogue.
Check Library > Achievements after the round; a Roblox profile badge is not required for every in-game achievement.
If it does not unlock, recheck the exact role, mode, player-count and public/private-server conditions before retrying.

This requirement is documented by the community Achievements table, revision 87931. It is not a developer API and may lag behind a patch.