Chapter 18 glgenvetexarrays(1)

[KHU-Interactive-Technology]

I've got error when executing the codes for chapter 18.

self.vao_ref = glGenVertexArrays(1)

Attempt to call an undefined function glGenVertexArrays, check for bool(glGenVertexArrays) before calling
File "C:\Users\Seungjae\Desktop\Chapter17\Object.py", line 12, in init
self.vao_ref = glGenVertexArrays(1)
^^^^^^^^^^^^^^^^^^^^
File "C:\Users\Seungjae\Desktop\Chapter17\ShaderTeapot.py", line 29, in
quat_teapot = Object("teapot")
^^^^^^^^^^^^^^^^
OpenGL.error.NullFunctionError: Attempt to call an undefined function glGenVertexArrays, check for bool(glGenVertexArrays) before calling