I think you have to download the google authenticator app and it'll give you a key, with that you can login. I don't remember exactly but this was the process.

How do I login to ivg from new device? Authenticator i dont have key. Password reset doesn’t work. Never get mail.

I am at chapter 6 only. Completed the big battle. I am more focused on side stuff like expanding camp lol.

Completed main story, not the game, just main story which is around 20 % of total game I think lol. Main story was OK nothing special. Mostly frustrating forgettable stuff. Im glad, im done with story and got bunch of good weapons and mounts. Now i can enjoy the good stuff which is the side content and faction quests. Real end game and fun stuff starts once you done with main story.