How to pass client certificate to WebSocket in Python?

How to pass client certificate to WebSocket in Python? What are the options for specifying paths to SSL certifcate and key?

I have following code:

import websocket

sslopt = {
    'check_hostname': False
}

ws = websocket.WebSocket(sslopt=sslopt)
ws = ws.connect('wss://domain.name/end-point/name')

print(ws.recv())

I works when I am connecting directly, to WebSocket server, but I need to connect to WebSocket server hidden behind nginx with SSL enabled.