HTML

make div center of screen bootstrap 5

<div class="d-flex justify-content-md-center align-items-center vh-100">
    <p>Your Content</p>
</div>

centralizing to the middle of the screen with bootstrap 5

<div class="d-grid gap-2 col-6 mx-auto">
  <button class="btn btn-primary" type="button">Button</button>
  <button class="btn btn-primary" type="button">Button</button>
</div>