Node.js Express res.sendFile ничего не делает при вызове в app.post

Когда я вызываю res.sendFile внутри app.post("/publish-score"...), ничего не происходит. Код состояния запроса — 200. Есть идеи?

Вот код моего приложения.

import express from "express";
import Boggle from "solve-boggle";
import { rateLimit } from "express-rate-limit";
import { dirname } from "path";
import { fileURLToPath } from "url";
import { readFileSync, writeFile } from "fs";
const __dirname = dirname(fileURLToPath(import.meta.url));

const app = express();
const PORT = process.env.PORT || 5001;

let user_name;
let board;

app.use(express.urlencoded({extended:true}));
app.use(express.static(__dirname));
app.use(express.json());

app.get("/", (req, res) => {
    res.sendFile(__dirname + "/public/index.html");
});

app.get("/new-board", (req, res) => {
    console.info("new board req: ", req.body);
    board = new Boggle(5);
    res.send(board);
});

app.get("/solution", (req, res) => {
    board.solve(words => {
        res.send(words);
    });
});

app.get("/name", (req, res) => {
    res.sendFile(__dirname + "/public/play.html");
})

// using get instead of post to prevent form resubmission
app.post("/name", (req, res) => {
    user_name = req.body.name;
    console.info("body: ", req.body);
    console.info("name: ", req.body.name);
    res.sendFile(__dirname + "/public/play.html");
});

// publish score
app.post("/publish-score", (req, res) => {
    console.info("request name: ", user_name);
    console.info("request score: ", req.body.score);

    let user_score = req.body.score;

    // read scores file
    let data = readFileSync("./data/scores.json", (error, data) => {
        if (error){
            console.info(error);
            return;
        };
    });
        
    // check if name already in score list
    let names = [];
    let scores_data = JSON.parse(data);
    scores_data.daily_puzzle.scores.map((entry) => names.push(entry.name));
    console.info("names: ", names);
    if (names.includes(user_name)) {
        console.info("Name used already!");
        res.sendFile(__dirname + "/public/dup_name.html");
        return;
    };

    // add name and score to list
    let push_name = user_name;
    let push_score = user_score;
    if (user_name == undefined){push_name = "NoName"}; 
    if (user_score == undefined){push_score = "NoScore"}; 
    scores_data.daily_puzzle.scores.push({
        "name": push_name,
        "score": push_score
    });

    // console.info(scores_data.daily_puzzle.scores);        

    writeFile("./data/scores.json", JSON.stringify(scores_data), (error) => {
        if (error) {
            console.info("An error has occurred ", error);
            return;
        }
        console.info("Data written successfully to the file");
    });  
    // }); 
});

app.listen(PORT, () => {console.info(`Listening on port ${PORT}`)});

Я бы хотел, чтобы сервер отправлял dup_name.html, когда пользователь пытается опубликовать партитуру с именем, которое уже есть в scores.json. Я пробовал переместить его в другое место в a[[.pot, но безуспешно.