The safest way to get the full text is to buy the official e-book. Major platforms offer the French edition:
The first book in the series, "Harry Potter et la Pierre Philosophale," sets the stage for the entire narrative. Published in 1997, the book introduces readers to the magical world, its history, and the beloved characters that drive the story forward. The story revolves around the Sorcerer's Stone, a powerful object that can grant eternal life, and Harry's quest to prevent it from falling into the wrong hands. Harry Potter Et La Pierre Philosophale Pdf Full Text