Does anybody know how many chapters are left till the end?

Probably alot more. This story only has like 10-14 pages per chapter (2-3 pages being "fillers", "promo", or intro pages) like a lot of webtoons. Because of this, I'm guessing it may have upwards of 50 to 80 chapters..maybe more, idk. All depends how popular the manga is really.

It's up to chapter 36 on the Korean site, and it's still in the midst of the drama, so unless it's going to have a predictable lezhin rushed ending, then seems like quite a few to go.