index.js

const Telegraf = require('telegraf');
const bot = new Telegraf("YOUR_TOKEN");
const axios = require('axios'); // add axios

bot.start((message) => {
  console.log('started:', message.from.id)
  return message.reply('Hello my friend, contact me by send /contact, or write anything');
})

bot.hears('hi', message => {
  return message.reply('Hey!');
});

bot.command('contact', message => {
  return message.reply('contact me at: pasquale.delucia96@gmail.com or @VarPGram');
});

bot.on('sticker', (message) => message.reply('👍'));

bot.on('text', message => {

  const subreddit = message.message.text;

  axios
    .get(`https://reddit.com/r/${subreddit}/top.json?limit=10`)
    .then(res => {
      const data = res.data.data;
      if (data.children.length < 1)
        return message.reply("The search on reddit haven't results.");

      const link = `https://reddit.com/${data.children[0].data.permalink}`;
      return message.reply(link);
    })

    .catch(err => {
      console.log(err);
      return message.reply('try to another search (in english) or contact me at: pasquale.delucia96@gmail.com or @VarPGram');
    });
});

bot.startPolling();