What’s the correct mark-up for custom radios and server-side validation?

Created by: martinbean

I’m having trouble rendering stacked custom radios with server-side validation.

My raw mark-up looks like this (a Laravel Blade template):

<div class="form-group">
    <label class="form-control-label">Category</label>
    <div class="custom-controls-stacked">
        @foreach($categories as $id => $name)
            <label class="custom-control custom-radio">
                <input type="radio" id="category-{{ $id }}" name="category_id" value="{{ $id }}" class="custom-control-input" {{ old('category_Id') == $id ? 'checked ' : '' }}/>
                <span class="custom-control-indicator"></span>
                <span class="custom-control-description">{{ $name }}</span>
            </label>
        @endforeach
    </div>
    @foreach($errors->get('category_id') as $error)
        <div class="invalid-feedback">{{ $error }}</div>
    @endforeach
</div>

Where is the appropriate place to put the .is-invalid class that both makes the radio inputs red, and displays the <div class="invalid-feedback"> elements?