How to set up CORS or OPTIONS for Rocket.rs

Question

I\'ve got a backend running rocket.rs which my flutter web app sends a request to, but it can\'t get past the OPTIONS response.

I have tried adding CORS (rocket_cors) t

Answer 1

Lambda Fairy's comment answered it for me.
I put it all in the GET Handler:

#[get("/")]
fn get_handler<'a>() -> Response<'a> {
    let mut res = Response::new();
    res.set_status(Status::new(200, "No Content"));
    res.adjoin_header(ContentType::Plain);
    res.adjoin_raw_header("Access-Control-Allow-Methods", "POST, GET, OPTIONS");
    res.adjoin_raw_header("Access-Control-Allow-Origin", "*");
    res.adjoin_raw_header("Access-Control-Allow-Credentials", "true");
    res.adjoin_raw_header("Access-Control-Allow-Headers", "Content-Type");
    res.set_sized_body(Cursor::new("Response")); 
    res