Please help me with tile and character

As i am using gdevelop for creating a game. I added a tile and gave it platform behavior and then i added a character and gave it platform character behavior. But when i run my program the character floats in the air and when i move it moves in the air (above the tile).
please help in this problem.

Maybe the hitbox of your player or platform is off?
Try adjusting the hitbox of the player to prevent him from floating. Or better yet, make a separate object for the player’s hitbox, make it as big as the player, and then position the player on top?