<!-- You have to change the data-toggle to data-bs-toggle and use data-bs-target attribute.
Add the ID in the collapse div.
That's all..
Believe me, it works-->
<button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#collapse" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="navbar-collapse collapse" id="collapse">