
mangago stops at chapter 8, so if you want to move on to chapter 9, you will have to get the 2nd volume, which has chapters 6~12
here: https://renta.papy.co.jp/renta/sc/frm/item/168410/title/686241/
make sure you are getting: MADK 2
as for volume 3, it is still being serialized, so it is still ongoing; so far chapters 13~16 have been released, and you can find them here:
https://renta.papy.co.jp/renta/sc/frm/item/234892/

oops sorry, this was meant for the comment below yours.
i think digital versions will be available upon the release date. volume 1 has a digital version on the sublime site, and I bet the 2nd volume will have one as well. you can check the website to see if it updates:
https://www.sublimemanga.com/read/manga/madk-2/product/825
I know I'm quite desperate but can anyone here provide a link as to where I can buy a digital copy of Volume 2? I can't buy the Vol.2 (English) paperback and a reader commented that the raws are available in Renta but I can't find it. Helppp...I badly want to read the continuation. I've been waiting for an update here in Mangago but it seems that it's been dropped so I wanted to try and buy the raws instead. ╥﹏╥