Show Hide password when click on eye icon using JavaScript in ASP.Net

Hi NarendraM,

Refer below sample code.

HTML

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.13.0/css/all.min.css" />
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap.min.css" />
<style>
    .container i {
        margin-left: -30px;
        cursor: pointer;
    }
</style>
<form id="form1" runat="server">
    <asp:TextBox ID="txtPassword" placeholder="Password" TextMode="Password" CssClass="form-control"
        runat="server" name="txtpassword" required></asp:TextBox>
    <i id="togglePassword" class="fa fa-eye"></i>
</form>
<script type="text/javascript">
    var togglePassword = document.querySelector('#togglePassword');
    var password = document.querySelector('#txtPassword');
    togglePassword.addEventListener('click', function (e) {
        const type = password.getAttribute('type') === 'password' ? 'text' : 'password';
        password.setAttribute('type', type);
        this.classList.toggle('fa-eye-slash');
    });
</script>

Screenshot