why isn't this code working? in Networkx

[layally]

Hello,
I am a beginner in python and I faced an issue with the code. I am trying to create nodes in a specific location, but there is an error and I am not sure how to solve it.
My code:
import networkx as nx
G = nx.Graph()
G.add_node(1, pos[2,6])
G.add_node(2, pos[4,6])
G.add_node(3, pos[6,6])
G.add_node(4, pos[8,6])
G.add_edges_from([(1,5), (1,13), (1,17), (1,21)])
G.add_edges_from([(2,10), (2,6), (2,18), (2,22)])
G.add_edges_from([(3,11), (3,15), (3,7), (3,23)])
G.add_edges_from([(4,12), (4,16), (4,20), (2,24)])

The problem occur In the nodes creation part it tells me [ KeyError: (2, 6) ]. Anyone who can fix this issue and lets the code run successfully ?