No date announced yet. Check out more in the Crunchyroll article as they are co-producing along with Aniplex. Series synopsis from AniList:
Back then, Dok-Ja had no idea. He had no idea his favorite web novel ‘Three Ways to Survive the Apocalypse’ was going to come to life, and that he would become the only person to know how the world was going to end. He also had no idea he would end up becoming the protagonist of this novel-turned-reality. Now, Dok-Ja will go on a journey to change the course of the story and save humankind once and for all.
The original webnovel is 552 chapters, the Webtoons adaptation is about a third of the way through it at 200+ episodes, and these aren’t short. I wonder what pacing they will go with. I think up through the 4th scenario at episode ~70 of the webtoon is a good stopping point, but that might be too fast and end up incoherent.