Why can’t i click the “register-selection” in bootstrap and JS?

I am making a website and I want to display an alert if the “register-selection” is clicked. But I can’t do it. Firstly; I tried to do it with Jquery but it did not work. After that; I tried it with the vanilla Javascript. But it did not work either. I tried to find the solution on the web and ChatGPT but I couldn’t find it again. How can I solve my Problem ?

<!DOCTYPE html>
<html>
<head>
    <meta charset='utf-8'>
    <meta http-equiv='X-UA-Compatible' content='IE=edge'>
    <title>Register/Login</title>
    <meta name='viewport' content='width=device-width, initial-scale=1'>
    <link rel='stylesheet' type='text/css' media='screen' href='main.css'>
    <link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-T3c6CoIi6uLrA9TneNEoa7RxnatzjcDSCmG1MXxSR1GAsXEV/Dwwykc2MPK8M2HN" crossorigin="anonymous">
    <script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.bundle.min.js" integrity="sha384-C6RzsynM9kWDrMNeT87bh95OGNyZPhcTNXj1NW7RuBCsyN/o0jlpcV8Qyq46cDfL" crossorigin="anonymous"></script>
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css" integrity="sha512-DTOQO9RWCH3ppGqcWaEA1BIZOC6xxalwEsw9c2QQeAIftl+Vegovlnee1c9QX4TctnWMn13TZye+giMm8e2LwA==" crossorigin="anonymous" referrerpolicy="no-referrer" />
    <script src="https://code.jquery.com/jquery-3.7.1.js" integrity="sha256-eKhayi8LEQwp4NKxN+CfCh+3qOVUtJn3QNZ0TciWLP4=" crossorigin="anonymous"></script>
    <script src='main.js'></script>
</head>
<style>
    body{
    background-color: #0A0A0A !important;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    gap: 6rem;
}


#register-login-selection{
    padding-top: 15rem;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: row;
    gap: 5rem;
    word-break: break-all;
}


#register-selection{
    width: 15%;
    text-align: center;
    cursor: pointer;
    word-break: break-all;
}


#register-selection>h1{
    color: #FFF08D;
}



#login-selection{
    width: 15%;
    text-align: center;
    cursor: pointer;
    word-break: break-all;
}


#login-selection>h1{
    color: #FFF08D;
}

#login-form{
    width: 30%;
    padding-top: 3rem;
    padding-bottom: 3rem;
    padding-left: 3rem;
    padding-right: 3rem;
    background-color: #0A0A0A;
    border: 0.1rem solid #292929;
}

label{
    color: #FFF08D;
}

input{
    background-color: #0A0A0A !important;
    border-color: #292929 !important;
    color: #6b6b6b !important;
}

.form-group{
    padding-bottom: 2em;
}

button{
    background-color: #FFF08D !important;
    color: #0A0A0A !important;
    border-color: #FFF08D !important;
}


button:hover{
    background-color: #1A1A1A !important; 
    color: #FFF !important;
}


#register-form{
    width: 30%;
    padding-top: 3rem;
    padding-bottom: 3rem;
    padding-left: 3rem;
    padding-right: 3rem;
    display: none;
    background-color: #0A0A0A;
    border: 0.1rem solid #292929;
}
</style>
<body>
    
    <div id="register-login-selection" class="container-fluid">
        
        <div id="register-selection" class="">
            <h1>Register</h1>
        </div>

        <div id="login-selection" class="">
            <h1>Log In</h1>
        </div>
    </div>



    <form id="login-form">
        <div class="form-group">
          <label for="exampleInputEmail1">Email address</label>
          <input type="email" class="form-control" id="exampleInputEmail1" aria-describedby="emailHelp" placeholder="Enter email">
        </div>
        <div class="form-group">
          <label for="exampleInputPassword1">Password</label>
          <input type="password" class="form-control" id="exampleInputPassword1" placeholder="Password">
        </div>
        <button type="submit" class="btn btn-primary">Submit</button>
    </form>


    <form id="register-form">
        <div class="form-group">
          <label for="exampleInputEmail1">Email address</label>
          <input type="email" class="form-control" id="exampleInputEmail1" aria-describedby="emailHelp" placeholder="Enter email">
        </div>
        <div class="form-group">
          <label for="exampleInputPassword1">Password</label>
          <input type="password" class="form-control" id="exampleInputPassword1" placeholder="Password">
        </div>
        <button type="submit" class="btn btn-primary">asd</button>
    </form>
</body>


</body>


<script>
    var RegisterButton=document.getElementById("register-selection");


    RegisterButton.addEventListener("click",function(){
        RegisterButton.style.color="red";
    })

</script>
</html>