Use the following css styles for carousel to work as expected.


.product_img_slide {
padding: 100px 0 0 0;
}

.product_img_slide > .carousel-inner > .carousel-item {
overflow: hidden;
max-height: 650px;
}

.carousel-inner {
position: relative;
width: 100%;
}

.product_img_slide > .carousel-indicators {
top: 0;
left: 0;
right: 0;
width: 100%;
bottom: auto;
margin: auto;
font-size: 0;
cursor: e-resize;
/* overflow-x: auto; */
text-align: left;
padding: 10px 5px;
/* overflow-y: hidden;*/
white-space: nowrap;
position: absolute;
}

.product_img_slide > .carousel-indicators li {
padding: 0;
width: 76px;
height: 76px;
margin: 0 5px;
text-indent: 0;
cursor: pointer;
background: transparent;
border: 3px solid #333331;
-webkit-border-radius: 0;
border-radius: 0;
-webkit-transition: all 0.7s cubic-bezier(0.22, 0.81, 0.01, 0.99);
transition: all 1s cubic-bezier(0.22, 0.81, 0.01, 0.99);
}

.product_img_slide > .carousel-indicators .active {
width: 76px;
border: 0;
height: 76px;
margin: 0 5px;
background: transparent;
border: 3px solid #c13c3d;
}

.product_img_slide > .carousel-indicators > li > img {
display: block;
/*width:114px;*/
height: 76px;
}

.product_img_slide .carousel-inner > .carousel-item > a > img, .carousel-inner > .carousel-item > img, .img-responsive, .thumbnail a > img, .thumbnail > img {
display: block;
max-width: 100%;
line-height: 1;
margin: auto;
}

.product_img_slide .carousel-control-prev {
top: 58%;
/*left: auto;*/
right: 76px;
opacity: 1;
width: 50px;
bottom: auto;
height: 50px;
font-size: 50px;
cursor: pointer;
font-weight: 700;
overflow: hidden;
line-height: 50px;
text-shadow: none;
text-align: center;
position: absolute;
background: transparent;
text-transform: uppercase;
color: rgba(255, 255, 255, 0.6);
-webkit-box-shadow: none;
box-shadow: none;
-webkit-border-radius: 0;
border-radius: 0;
-webkit-transition: all 0.6s cubic-bezier(0.22, 0.81, 0.01, 0.99);
transition: all 0.6s cubic-bezier(0.22, 0.81, 0.01, 0.99);
}

.product_img_slide .carousel-control-next {
top: 58%;
left: auto;
right: 25px;
opacity: 1;
width: 50px;
bottom: auto;
height: 50px;
font-size: 50px;
cursor: pointer;
font-weight: 700;
overflow: hidden;
line-height: 50px;
text-shadow: none;
text-align: center;
position: absolute;
background: transparent;
text-transform: uppercase;
color: rgba(255, 255, 255, 0.6);
-webkit-box-shadow: none;
box-shadow: none;
-webkit-border-radius: 0;
border-radius: 0;
-webkit-transition: all 0.6s cubic-bezier(0.22, 0.81, 0.01, 0.99);
transition: all 0.6s cubic-bezier(0.22, 0.81, 0.01, 0.99);
}

.product_img_slide .carousel-control-next:hover, .product_img_slide .carousel-control-prev:hover {
color: #c13c3d;
background: transparent;
}



Here is a Corousel widget that is an extension of yii\bootstrap5\Carousel, to show image thumbnails as indicators for the carousel.
Here is the widget code.
<?php
namespace app\widgets;
use Yii;
use yii\bootstrap5\Html;

class Carousel extends \yii\bootstrap5\Carousel
{
public $thumbnails = [];

public function init()
{
parent::init();
Html::addCssClass($this->options, ['data-bs-ride' => 'carousel']);
if ($this->crossfade) {
Html::addCssClass($this->options, ['animation' => 'carousel-fade']);
}
}

public function renderIndicators(): string
{
if ($this->showIndicators === false){
return '';
}
$indicators = [];
for ($i = 0, $count = count($this->items); $i < $count; $i++){
$options = [
'data' => [
'bs-target' => '#' . $this->options['id'],
'bs-slide-to' => $i
],
'type' => 'button',
'thumb' => $this->thumbnails[$i]['thumb']
];
if ($i === 0){
Html::addCssClass($options, ['activate' => 'active']);
$options['aria']['current'] = 'true';
}

$indicators[] = Html::tag('li',Html::img($options['thumb']), $options);
}
return Html::tag('ol', implode("\n", $indicators), ['class' => ['carousel-indicators']]);
} }

You can use the above widget in your view file as below:
<?php
$indicators = [
'0' =>[ 'thumb' => "https://placehold.co/150X150?text=A"],
'1' => ['thumb' => 'https://placehold.co/150X150?text=B'],
'2' => [ 'thumb' => 'https://placehold.co/150X150?text=C']
];
$items = [
[ 'content' =>Html::img('https://live.staticflickr.com/8333/8417172316_c44629715e_w.jpg')],
[ 'content' =>Html::img('https://live.staticflickr.com/3812/9428789546_3a6ba98c49_w.jpg')],
[ 'content' =>Html::img('https://live.staticflickr.com/8514/8468174902_a8b505a063_w.jpg')]
];

echo Carousel::widget([
'items' =>
$items,
'thumbnails' => $indicators,
'options' => [
'data-interval' => 3, 'data-bs-ride' => 'scroll','class' => 'carousel product_img_slide',
],

]);