Correct syntax for including the symbol in an isolated margin user data stream

Hi there. I’m trying to get a user data stream feed for an isolated margin account/symbol. I need to pass the symbol which is a mandatory parameter but I’m not sure what the url should look like.
Can anyone help me by providing an example. I’ve tried the following but am getting a 400 error:

You should generate a listenkey via the restful endpoint first (Binance API Documentation).
For example, /sapi/v1/userDataStream/isolated?symbol=BTCUSDT

With the listenkey, you subscribe to the user data stream. wss://<listenKey>