Вы можете использовать последнюю Bootstrap 4 Accordion. Подробнее об этом здесь https://getbootstrap.com/docs/4.3/components/collapse/#accordion -пример
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.5.0/css/bootstrap.min.css" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.5.0/js/bootstrap.min.js"></script>
<div class="accordion" id="accordionExample">
<div class="card">
<div class="card-header" id="heading-1">
<h2>
<button class="btn btn-link" type="button" data-toggle="collapse" data-target="#collapse-1" aria-expanded="true" aria-controls="collapse-1">
111
</button>
</h2>
</div>
<div id="collapse-1" class="collapse show" aria-labelledby="heading-1" data-parent="#accordionExample">
<div class="card-body">
111
</div>
</div>
</div>
<div class="card">
<div class="card-header" id="heading-2">
<h2>
<button class="btn btn-link collapsed" type="button" data-toggle="collapse" data-target="#collapse-2" aria-expanded="false" aria-controls="collapse-2">
222
</button>
</h2>
</div>
<div id="collapse-2" class="collapse" aria-labelledby="heading-2" data-parent="#accordionExample">
<div class="card-body">
222
</div>
</div>
</div>
<div class="card">
<div class="card-header" id="heading-3">
<h2>
<button class="btn btn-link collapsed" type="button" data-toggle="collapse" data-target="#collapse-3" aria-expanded="false" aria-controls="collapse-3">
333
</button>
</h2>
</div>
<div id="collapse-3" class="collapse" aria-labelledby="heading-3" data-parent="#accordionExample">
<div class="card-body">
333
</div>
</div>
</div>
</div>
Итак, ваш код будет
<div class="accordion" id="accordionExample">
<?php $x = 0; ?>
<?php foreach ($testFaqs as $faqs) { ?>
<div class="card">
<div class="card-header" id="heading-<?php echo $x; ?>">
<h2>
<button class="btn btn-link" type="button" data-toggle="collapse" data-target="#collapse-<?php echo $x; ?>" aria-expanded="true" aria-controls="collapse-<?php echo $x; ?>">
<?php echo $faqs['name']; ?>
</button>
</h2>
</div>
<div id="collapse-<?php echo $x; ?>" class="collapse<?php if ($x == 0) { ?> show<?php } ?>" aria-labelledby="heading-<?php echo $x; ?>" data-parent="#accordionExample">
<div class="card-body">
<?php if ($faqs['videoUrl'] != '' ) { ?>
<iframe align="center" class="youtube" src="https://www.youtube.com/embed/<?php echo $faqs['videoUrl']?>"></iframe>
<?php } ?>
<?php echo htmlspecialchars_decode(($faqs['answer'])); ?>
</div>
</div>
</div>
<?php $x++; } ?>
</div>
Добавлен этот class="collapse<?php if ($x == 0) { ?> show<?php } ?>"
для первого открываемого окна.
Если у вас более одной гармошки на одной странице - не забудьте изменить id="accordionExample"
и data-parent="#accordionExample"
, возможно, добавив им приращение для подсчета аккордеонов.