Bootstrap class: .form-select-lg

    <select class="form-select-lg" aria-label="select example">
      <option value="">Choose...</option>
      <option value="1">Option 1</option>
      <option value="2">Option 2</option>
      <option value="3">Option 3</option>
    </select>

Preview

Tips 💡

You don't need to remember all CSS classes. Just use the Bootstrap Editor instead.

More in Bootstrap Forms

Bootstrap 4 & 5

Tailwind