如何根据其他字段值将“required”属性添加到输入字段

I have these input fields:

我有这些输入字段：

<input class="text_field" id="ProfilePhoneNumber" phone-by-state="User.PhoneNumber" type="text" required/>

<div class="btn-group">
    <button multi-select="User.Notifications.Phone" class="btn btn-default dropdown-toggle">
        Select Severities <span class="caret"></span></button>
    <ul multi-select-dropdown class="dropdown-menu">
        <li>
            <input type="checkbox" id="NotificationsPhone_1"
                   ng-model="User.Notifications.Phone.High">
            <label for="NotificationsPhone_1">High</label>
        </li>
        <li>
            <input type="checkbox" id="NotificationsPhone_2"
                   ng-model="User.Notifications.Phone.Medium">
            <label for="NotificationsPhone_2">Medium</label>
        </li>
        <li>
            <input type="checkbox" id="NotificationsPhone_3"
                   ng-model="User.Notifications.Phone.Low">
            <label for="NotificationsPhone_3">Low</label>
        </li>
    </ul>
</div>

<div><input id="SMS" type="checkbox"
       ng-model="User.SMS.Enabled">SMS Enable
</div>
<input