Mulitcheckbox : I am able to check only one checkbox

There are 2 checkboxes displayed in a grid cell. I am able to check only one checkbox. If I click on the another, it' checking the first one. How to make the other checkbox active. here is my html:

    <div class="inline-div" *ngFor="let item of to.labels | keyvalue; let idx=index">
<input type="checkbox" id="item">
<label class="form-check-label" for="item"></label>
</div>

Please suggest how to make sure the other checkbox is been checked.