Why doesn't get route with :id work in Express?

Question

Express.js

Why doesn't get route with :id work for me at all?
After some time, I realized that the error lies on the server, although I'm not completely sure.

Files:

Here get doesn't work at all, even console.log() does nothing. link.routes.js

const {Router} = require("express");
const auth = require("../middleware/auth.middleware");
const config = require("config");
const shortid = require("shortid");
const Link = require("../models/Link");

const router = new Router();

router.post("/generate", auth, async (req, res) => {
  try {
    const baseUrl = config.get("baseUrl");
    const {from} = req.body;

    const code = shortid.generate();

    const existing = await Link.findOne({ from });

    if(existing){
      return res.json({ link: existing })
    }

    const to = baseUrl + "/t/" + code;

    const link = new Link({
      code, to, from, owner: req.user.userId
    });

    await link.save();

    res.status(200).json({ link });

  } catch (e) {
    res.status(500).json({ error: "Что-то пошло не так, попробуйте снова" });
  }
});
router.get("/", auth, async (req, res) => {
  try {
    const links = await Link.find({ owner: req.userId });
    res.json(links);

  } catch (e) {
    res.status(500).json({ error: "Что-то пошло не так, попробуйте снова" });
  }
});
router.get("/:id", auth, async (req, res) => {
  try {
    const link = await Link.findById(req.params.id);
    res.json(link);

  } catch (e) {
    res.status(500).json({ error: "Что-то пошло не так, попробуйте снова" });
  }
});

module.exports = router;

app.js

const express = require("express");
const config = require("config");
const mongoose = require("mongoose");

const app = express();

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

app.use("/api/auth", require("./routes/auth.routes"));
app.use("/api/link", require("./routes/link.routes"));

const PORT = config.get("port") | 5000;

async function start(){
  try {
    await mongoose.connect(config.get("mongoUri"), {
      useNewUrlParser: true,
      useUnifiedTopology: true,
      useCreateIndex: true
    });
    app.listen(PORT, () => console.log(`App has been started on ${PORT}!...`));
  } catch (e) {
    console.log("Server error", e.message);
    process.exit(1);
  }
}
start();

client/routes.js

import React from "react";
import {Switch, Route, Redirect} from "react-router-dom";
// pages
import {LinksPage} from "./pages/LinksPage";
import {CreatePage} from "./pages/CreatePage";
import {DetailPage} from "./pages/DetailPage";
import {AuthPage} from "./pages/AuthPage";

export const useRoutes = (isAuth) => {
  if(isAuth){
    return (
      <Switch>
        <Route path="/links" exact>
          <LinksPage />
        </Route>
        <Route path="/create" exact>
          <CreatePage />
        </Route>
        <Route path="/detail/:id"> // тут :id тоже поставлен
          <DetailPage />
        </Route>
        <Redirect to="/create" />
      </Switch>
    )
  }

  return (
    <Switch>
      <Route path="/" exact>
        <AuthPage />
      </Route>
      <Redirect to="/" />
    </Switch>
  )
}

client/pages/DetailPage.js

import React, {useState, useEffect, useCallback, useContext} from "react";
import {useParams} from "react-router-dom";
import {useHttp} from "../hooks/http.hook";
import {AuthContext} from "../context/auth.context";
// components
import {Loader} from "../components/Loader";
import {LinkCard} from "../components/LinkCard";

export const DetailPage = () => {
  const {request, loading} = useHttp();
  const {token} = useContext(AuthContext);
  const [link, setLink] = useState(null);
  const linkId = useParams().id;

  const getLink = useCallback(async () => {
    try {
      const fetched = await request(`/api/link/${linkId}`, "GET", null, {
        Auth: `Bearer ${token}`
      });
      // все что пишу после request функции, не работает
      setLink(fetched);
    } catch (e) {}
  }, [request, token, linkId]);

  useEffect(() => {
    getLink();
  }, [getLink]);

  if(loading){
    return <Loader />
  }

  return (
    <>
      { !loading && link && <LinkCard link={link} /> }
    </>
  )
};

The request function simply does a fetch() with the parameters specified in the function.

What to do?