Rust Tokio Tungstenite Failed to connect: HTTP error: 400 Bad Request

Question

I am programming in Rust, creating a websocket client using tokio_tungstenite. However, I am getting a rather peculiar error. My code is below:

use std::env;
use futures::{SinkExt, StreamExt};
use tokio_tungstenite::tungstenite::protocol::Message;
use tokio_tungstenite::connect_async;

#[tokio::main]

async fn main() {

    env::set_var("RUST_BACKTRACE", "1");

    let url = "wss://ws-feed.exchange.coinbase.com";
    let msg = r#"
    {
        "type": "subscribe",
        "product_ids": [
            "ETH-USD"
        ],
        "channels": [
            "level2",
            "heartbeat",
            {
                "name": "ticker",
                "product_ids": [
                    "ETH-USD"
                ]
            }
        ]
    }"#;

    match connect_async(url).await {
        Ok((ws_stream, _)) => {
            let (mut write, mut read) = ws_stream.split();

            match write.send(Message::Text(msg.to_string())).await {
                Ok(_) => println!("Message sent successfully"),
                Err(e) => println!("Failed to send message: {}", e),
            }

            while let Some(msg) = read.next().await {
                match msg {
                    Ok(msg) => println!("Received: {}", msg),
                    Err(e) => println!("Error reading message: {}", e),
                }
            }
        },
        Err(e) => println!("Failed to connect: {}", e),
    }
}

Cargo.toml:

[dependencies]
futures = "0.3"
tokio = { version = "1", features = ["full"] }
tokio-tungstenite = "0.15.0"

My error:

Failed to connect: HTTP error: 400 Bad Request

The reason it's peculiar is that the url works. I have a websocket client extension in Mozilla FireFox that I used the same url: wss://ws-feed.exchange.coinbase.com and message:

{
        "type": "subscribe",
        "product_ids": [
            "ETH-USD"
        ],
        "channels": [
            "level2",
            "heartbeat",
            {
                "name": "ticker",
                "product_ids": [
                    "ETH-USD"
                ]
            }
        ]
    }

and it works. The extension is called Websocket Weasel.

The reason I have the backtrace in the code is because before I didn't include the match and I had a bad error that disappeared when I used the match, but now it compiles but without much information. Below was the error I had:

3: enum2$<core::result::Result<tuple$<tokio_tungstenite::WebSocketStream<enum2$<tokio_tungstenite::stream::MaybeTlsStream<tokio::net::tcp::stream::TcpStream> > >,http::response::Response<tuple$<> > >,enum2$<tungstenite::error::Error> > >::expect<tuple$<tokio

I am certain the error is in regards to the connection of the URL to the server. Any help would be greatly appreciated. You are awesome!