Novel

https://www.readlightnovel.org/the-beginning-after-the-end

Hello, this is the website I used to read this series. I've linked the first 3 books but there are more.
Book 1 = https://archive.bookfrom.net/turtleme/220842-the_beginning_after_the_end_early_years_book_1.html
Book 2 = https://archive.bookfrom.net/turtleme/220840-the_beginning_after_the_end_new_heights_book_2.html
Book 3 =
https://archive.bookfrom.net/turtleme/218872-the_beginning_after_the_end_beckoning_fates_book_3.html

However a website which has all of the chapters in one place is this although there are the occasional mistakes =
https://webnovelonline.com/novel/the_beginning_after_the_end

I really hope this helped :)

Wow I just remember in 2018 reading their novel on their own website. I don't remember what it is anymore tho since it's been so long

Thank you so much!(⌒▽⌒)

It's this one
https://tbatenovel.com/