我应该如何在rust中强制jsonwebtokens的反序列化类型？

[dependencies]
serde = "1.0"
serde_json = "1.0"

extern crate serde;
extern crate serde_json;

use serde::{Deserialize, Serialize};

#[derive(Debug, Serialize, Deserialize)]
struct JwtPayload {
    sub: String,
    exp: u64,
    // 其他您想要的字段
}

use serde_json::Value;

fn parse_jwt(jwt: &str) -> Result<JwtPayload, Box<dyn std::error::Error>> {
    let token = jwt.split('.').nth(1).unwrap_or("");
    let payload = base64::decode_config(token, base64::URL_SAFE_NO_PAD)?;
    let json: Value = serde_json::from_slice(&payload)?;
    let payload: JwtPayload = serde_json::from_value(json)?;
    Ok(payload)
}