“In the former film, the deceased Sith lord, still in his full black armor, is set ablaze atop a funeral pyre on land.“

Anakin appears as a force ghost at the end of the film alongside fellow Jedi Obi-Wan and Yoda. In the case of the others, we saw in the films that their bodies vanished as they died. There is every reason to think that Anakin’s body similarly vanished off-screen and the funeral pyre was just to burn the Darth Vader armor.