When The Phone Rings source...

When the phone rings is adapted from the web novel “지금 거신 전화는" (The Number You Have Dialed)  by 건어물녀 (Geon Eomul Nyeo)
There Is No Translated Version.
Original Version (Novel) https://page.kakao.com/content/60652458?tab_type=overview 
Original Version (Webtoon) https://page.kakao.com/content/65201745?tab_type=overview