TryHackMe — CyberHeroes

This challenge starts with the following information:

Want to be a part of the elite club of CyberHeroes? Prove your merit by finding a way to log in!

I visited the site in my browser by navigating to the following page:

http://<ipaddress>

There is a login page, which I visited.

Upon viewing the source code, I saw that the username and password were stored in plain text inside an if statement:

function authenticate() {
  a = document.getElementById('uname')
  b = document.getElementById('pass')
  const RevereString = str => [...str].reverse().join('');
  if (a.value==="h3ck3rBoi" && b.value===RevereString("54321@terceSrepuS")) { 
    var xhttp = new XMLHttpRequest();
    xhttp.onreadystatechange = function() {
      if (this.readyState == 4 && this.status == 200) {
        document.getElementById("flag").innerHTML = this.responseText;
        document.getElementById("todel").innerHTML = "";
        document.getElementById("rm").remove();
      }
    };
    xhttp.open("GET", "RandomLo0o0o0o0o0o0o0o0o0o0gpath12345_Flag_"+a.value+"_"+b.value+".txt", true);
    xhttp.send();
  }
  else {
    alert("Incorrect Password, try again.. you got this hacker!");
  }
}

After pasting in the username and reversing the password, I was able to log in and received the flag.