Getting new chapters for manga like 'That Witch' can be a challenge since scanlation groups are the primary source for a lot of these Korean titles. I usually check the aggregator sites, but they're often days or weeks behind the official Korean release, and the quality is wildly inconsistent. The official English version through platforms like Tapas or Tappytoon is the most reliable for speed and supporting the creators, but they operate on a coin system, so it's not exactly free.
For the absolute latest, some discord servers dedicated to specific series have fan translators who post rough versions almost as soon as the raw Korean chapter drops. It's a messy process, though, and the translations can be, uh, creative. Sometimes I just wait for the Tapas update later in the week because the official translation usually captures the nuance better, especially for character interactions.