I don't know what you mean by giveaway, but Play-4 Player Chess & Variants or this hyperlink should bring up all the chess.com variants: https://www.chess.com/variants
You can use the search bar there to search by variant name. Chaturaji is still there (just checked now), so maybe it moved for some reason?
Some variants are missing and aren't accessible on certain days. Yesterday there was a 4P giveaway, but I don't see any 4P giveaway variant today, the same thing happened with Chaturaji or any variant. Can someone answer me why?