Starts downloading Firefox instead of using one present in the system.

[malaire]

I tried following code on Debian 13. It immediately starts downloading Firefox instead of using the one already present in the system.

How can I disable auto-download? Program should NEVER download something implicitly.
How can I make this use the installed Firefox?

[dependencies]
anyhow = "1.0.102"
rustenium = "1.1.10"
tokio = { version = "1", features = [ "full" ] }

use anyhow::Result;
use rustenium::browsers::{BidiBrowser, firefox};

#[tokio::main]
async fn main() -> Result<()> {
    let mut browser = firefox(None).await;
    browser.navigate("https://markuslaire.com").await?;
    browser.screenshot().await?;
    browser.close().await?;
    Ok(())
}

EDIT: I tried also with chrome - same problem.