you need specific 'edges' in 'add_conditional_edges'
Method 1:

graph_builder.add_conditional_edges(
    "node", routing_function, path_map
)

Method 2:

def routing_function(state: State) -> typing.Literal['node_1', 'node_2]:
    pass

graph_builder.add_conditional_edges(
    "node", routing_function
)