You probably don't want to test what type of tile your player is touching that way.
An easier way to check if your player is touching a tile that has grass in your example is to use the Is Overlapping at Offset trigger
Offset X =0
Offset Y = - 20 (or however far down from the origin of the player you need to check)
First check if its overlapping a ground tile, then test if that tile is a "grass" tile (by comparing the animation frame number, or grass tile sprite depending on how you set it up)