bootstrap-show-password
Bootstrap 4 show input password when click on icon
include plugin file
<script src="bootstrap-show-password.js"></script>
Example
<div class="input-group"> <input type="password" name="user_password" id="user_password" class="form-control" data-toggle="password"> <div class="input-group-append"> <span class="input-group-text"><i class="fa fa-eye"></i></span> </div> </div>