If you're asking about the 'Dear X' series, there's a whole bunch of confusion about the titles because there are multiple manhwa/webtoons with similar names. The one I think you mean is 'Dear X: How to Survive as a Maid in a Horror Game'? That's the full title of the one that blew up. The official place is Webtoon, obviously, but their free model uses daily passes, which can be a drag if you're trying to binge. You read the latest episodes free, but for the back catalogue, you either wait for daily free unlocks or use coins.
I see a lot of people suggesting aggregator sites, and yeah, they have it all unlocked, but the translation quality is a total gamble. Sometimes it's decent, other times it's hilariously bad and messes with the plot. The official Webtoon version is definitely the most polished, and supporting the creators is a good thing, but the pacing is slower. Honestly, my routine is to read the new free episodes on Webtoon and then, if I get too impatient for a specific past arc, I might peek at an aggregator just for that chunk, even though I feel a little guilty about it. The art in 'Dear X' is too good to ruin with a sloppy translation, so it's a trade-off.