'error': {'code': -32700, 'message': 'Parse error'}

[TitusWongCN]

When I run codes below,

from neorpc.Client import RPCClient

client = RPCClient()
blockchain_height = client.get_height()
print(blockchain_height)

it returns this,

{'jsonrpc': '2.0', 'id': None, 'error': {'code': -32700, 'message': 'Parse error'}}

how can I get the correct value?