How to use proxies with Rust reqwest

[dependencies]
reqwest = { version = "0.13", features = ["socks"] } # "socks" only for SOCKS5
tokio = { version = "1", features = ["full"] }

use std::time::Duration;

#[tokio::main]
async fn main() -> Result<(), reqwest::Error> {
    let proxy = reqwest::Proxy::all("http://HOST:PORT")?
        .basic_auth("USERNAME", "PASSWORD");

    let client = reqwest::Client::builder()
        .proxy(proxy)
        .timeout(Duration::from_secs(30))
        .build()?;

    let ip = client.get("https://api.ipify.org").send().await?.text().await?;
    println!("exit IP: {ip}");
    Ok(())
}

let proxy = reqwest::Proxy::all("socks5h://USERNAME:PASSWORD@HOST:PORT")?;
let client = reqwest::Client::builder().proxy(proxy).build()?;

let ip = client.get("https://api.ipify.org").send().await?.text().await?;
println!("{ip}");

use reqwest::{Client, Proxy};

fn client_for(line: &str) -> reqwest::Result<Client> {
    let p: Vec<&str> = line.trim().splitn(4, ':').collect();
    let proxy = Proxy::all(format!("http://{}:{}", p[0], p[1]))?.basic_auth(p[2], p[3]);
    Client::builder().proxy(proxy).build()
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let list = std::fs::read_to_string("proxies.txt")?;
    for (i, line) in list.lines().filter(|l| !l.trim().is_empty()).enumerate() {
        let client = client_for(line)?;
        let ip = client.get("https://api.ipify.org").send().await?.text().await?;
        println!("{i}: {ip}");
    }
    Ok(())
}