I tried to implement Bootstrap 4 custom control for a checkbox by following the documentation, but the checkbox isn't appearing. Can anyone spot what I might be doing incorrectly?
<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" rel="stylesheet"/>
<div class="card-body"><label>Add Product Variant for </label>
<div class="form-group"><label for="formGroupExampleInput">Code</label><input type="text" class="form-control" placeholder="Enter Name"></div>
<div class="form-group"><label for="formGroupExampleInput">Name</label><input type="text" class="form-control" placeholder="Enter Name"></div>
<div class="form-group"><label for="formGroupExampleInput2">Description</label><textarea class="form-control" placeholder="Description"></textarea></div>
<div class="form-group">
<div class="custom-control custom-checkbox"><label for="formGroupExampleInput2">Default</label><input type="checkbox" class="custom-control-input" id="customControlValidation1"></div>
</div>
<hr>
<div class="form-group">
<div class="col-12"><button type="button" class="btn btn-default float-right">Add</button><button type="button" class="btn btn-danger float-right">Cancel</button></div>
</div>
</div>