I want to make the following field (settings) in my form as a required field in. How can I do it?

```
<div class="form-group">
    <label class="col-xs-5 control-label"> Settings*</label>

    <div class="col-xs-7">
        <ui-select multiple tagging="adPreferredEmailDomainPatternTransform" id="emailDomainPatternListInput"
                   tagging-tokens="SPACE|," theme="bootstrap"
                   ng-disabled="settings.enableAuthentication == 'false'"
                   ng-model="settings.emailDomainPatternList">
            <ui-select-match>{{$item.displayFormat}}</ui-select-match>
            <ui-select-choices repeat="item in emailDomainPatterns">
                {{item.displayFormat}}
            </ui-select-choices>
        </ui-select>
    </div>
</div>

```