Where did spell check go in Proton Drive docs?

I could have sworn there used to be spell check in the docs I created in Proton Drive, but was editing a doc today and realized that my typos aren't being highlighted. Do I need to manually turn it on somewhere? The only thing I could find in a google search was someone else complaining about the same thing, but no solutions. Is there a way to turn on spell check? If not, that seems like a massive oversight!