According to the One Piece Wiki, after the two-year timeskip, Sanji has managed to learn how to use Haki, and currently, he is a user of both the Color of Observation and the Color of Armament. Sanji is an extremely skilled Haki user, and he managed to learn all by himself, which is considered an incredible feat. Sanji has displayed his immense affinity for Observation Haki on more than a few occasions, and according to the author of the series, Sanji is especially accustomed to using this type of Haki at a very high level. Sanji is also a skilled user of Armament Haki and has displayed the skill on several occasions, especially in the Wano Country arc. Therefore, Sanji is a user of both Observation and Armament Haki.