Plant cells do not show endocytosis because
They have a rigid cell wall and internal turgor pressure
Endocytosis is an invagination of the cell surface to form an intracellular membrane-bounded vesicle containing extracellular fluid. This concludes that to perform endocytosis, the cell surface has to be flexible enough to allow movement. But the internal turgor pressure and rigid cell wall of a plant cell does not allows that.