سلام وقت بخیر
مشکلات کدنویسیش زیاد بود. کدتون رو بازنویسی کردم به این صورت:

کدتون رو ادیت کردم هرجاش رو خواستید می تونید تغییر بدید:
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<style>
.accordion {
border-top-left-radius: 1rem;
border-top-right-radius: 1rem;
border-bottom-left-radius: 1rem;
border-bottom-right-radius: 1rem;
direction: rtl;
margin-top: 1rem;
background-color: #eee;
color: #444;
cursor: pointer;
padding: 18px;
width: 100%;
border: none;
text-align: right;
outline: none;
font-size: 15px;
transition: 0.4s;
}
.active, .accordion:hover {
border-top-left-radius: 1rem;
border-top-right-radius: 1rem;
border-bottom-left-radius: 0rem;
border-bottom-right-radius: 0rem;
background-color: #ccc;
}
/* .accordion:after {
content: '\002B';
color: #fff;
font-weight: bold;
float: left;
margin-left: 10px;
background-color: #4155f2;
border-radius: 50%;
} */
.accordion-button::after {
margin-right: auto;
margin-left: unset !important;}
.active:after {
background-color: #000;
content: "\2212";
}
.panel {
direction: rtl;
border-bottom-left-radius: 1rem;
border-bottom-right-radius: 1rem;
padding: 0 18px;
background-color: #00ffff;
max-height: 0;
overflow: hidden;
transition: max-height 0.5s ease-out;
}
</style>
</head>
<body>
<div class="accordion accordion-flush" id="accordionFlush">
<div class="accordion-item">
<h2 class="accordion-header" id="headingOne">
<div class="pannel-heading" data-bs-toggle="collapse" data-bs-target="#collapseOne" aria-expanded="true" aria-controls="collapseOne">
<button class="accordion-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseOne" aria-expanded="false" aria-controls="collapseTwo">
عنوان آکارئون اینجا وارد شود
</button>
</div>
</h2>
<div id="collapseOne" class="accordion-collapse collapse show" aria-labelledby="headingOne" data-bs-parent="#accordionFlush">
<div class="accordion-body my-3">
<strong>توضیحات</strong> در اینجا وارد شود...
<div>
<a href="#" class="btn btn-outline-dark btn-md mt-3">عنوان کلید</a>
<!-- needs spacing -->
</div>
</div>
</div>
</div>
<div class="accordion-item">
<h2 class="accordion-header" id="headingTwo">
<button class="accordion-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseTwo" aria-expanded="false" aria-controls="collapseTwo">
عنوان آکارئون اینجا وارد شود
</button>
</h2>
<div id="collapseTwo" class="accordion-collapse collapse" aria-labelledby="headingTwo" data-bs-parent="#accordionFlush">
<div class="accordion-body">
<strong>توضیحات</strong> در اینجا وارد شود...
<div>
<a href="#" class="btn btn-outline-dark btn-md mt-3">عنوان کلید</a>
</div>
</div>
</div>
</div>
<div class="accordion-item">
<h2 class="accordion-header" id="headingThree">
<button class="accordion-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseThree" aria-expanded="false" aria-controls="collapseThree">
عنوان آکارئون اینجا وارد شود
</button>
</h2>
<div id="collapseThree" class="accordion-collapse collapse" aria-labelledby="headingThree" data-bs-parent="#accordionFlush">
<div class="accordion-body">
<strong>توضیحات</strong> در اینجا وارد شود...
<div>
<a href="#" class="btn btn-outline-dark btn-md mt-3">عنوان کلید</a>
</div>
</div>
</div>
</div>
</div>
<script>
let target = $(".collapse:not(.collapsed)").get(0);
$(".collapse").on("show.bs.collapse", function(e) {
target = e.target;
});
$(".collapse").on("hide.bs.collapse", function(ee) {
if (ee.target == target)
return false;
});
</script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.6.1/jquery.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/js/bootstrap.bundle.min.js" integrity="sha384-MrcW6ZMFYlzcLA8Nl+NtUVF0sA7MsXsP1UyJoMp4YLEuNSfAP+JcXn/tWtIaxVXM" crossorigin="anonymous"></script>
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-EVSTQN3/azprG1Anm3QDgpJLIm9Nao0Yz1ztcQTwFspd3yD65VohhpuuCOmLASjC" crossorigin="anonymous">
</body>
</html>