Hello! "Clue" is the root in English. Meaning: similar to "hint", "help", or "suggestion". Therefore, "Clue-ING" means that some (but not ALL) information is given to the recipient.

I don’t understand the example either, and I’m English 🤣 Maybe it’s US-English?

While CLUE is more often use as a noun, it is sometimes used as a verb, meaning to give a clue. That's what happening in this example. Synonyms include: indicate, suggest.