is there a way to iterate over key, values in a map about minijinja HOT 3 CLOSED

pub fn jwt(_state: &State, claims: Value, signing_key: Option<Value>) -> Result<String, Error> {
    let mut claims: HashMap<String, serde_json::Value> =
        serde_json::from_str(claims.to_string().as_str()).unwrap();

    // in case the expiry is missing, we expire it in 15min
    if claims.contains_key(EXPIRY).not() {
        let expire_in = Utc::now()
            .add(Duration::minutes(15))
            .with_second(0)
            .unwrap()
            .timestamp();
        claims.insert(EXPIRY.to_string(), serde_json::Value::from(expire_in));
    }

    let token = jsonwebtoken::encode(
        &Header::default(),
        &claims,
        &EncodingKey::from_secret(b"secret"),
    );

    token.map_err(|e| {
        Error::new(
            ErrorKind::UndefinedError,
            "jsonwebtoken failed to encode the token.",
        )
        .with_source(e)
    })
}