How to subscribe to websocket to get json data

[dpuact]

The subscription address is as follows:
ws://host:port/api/ws
First,I need to connect.Then I send a subscription message:

{
    "authCmd": {
        "cmdId": 0,
        "token": ""
    },
    "cmds": [
        {
            "entityType": "DEVICE",
            "entityId": "71da9c40-9ce9-11ef-a2c5-87c7805860a6",
            "cmdId": 10,
            "type": "TIMESERIES"
        },{
            "entityType": "DEVICE",
            "entityId": "226528f0-9cea-11ef-a2c5-87c7805860a6",
            "cmdId": 10,
            "type": "TIMESERIES"
        }
    ]
}

I didn't find how to use websocket in the documentation