bootstrap.bundle.js which contains Popper.js. Popper.js isn’t used to position dropdowns in navbars though as dynamic positioning isn’t required.
You need to wrap the dropdown’s toggle (your button or link) and the dropdown menu within
.dropdown, or another element that declares
position: relative;. Dropdowns can be triggered from
<button> elements to better fit your potential needs.
Below is an example of a dropdown with the Grace styling. You will need to add the
.dropdown-border class in order to overwrite the default Bootstrap styling.
<label>Dropdown</label><div class="dropdown dropdown-border"><button class="btn btn-link dropdown-toggle" type="button" id="dropdownMenuButton" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Dropdown button</button><div class="dropdown-menu" aria-labelledby="dropdownMenuButton"><a class="dropdown-item" href="#">Action</a><a class="dropdown-item" href="#">Another action</a><a class="dropdown-item" href="#">Something else here</a></div></div>
If you want to see more examples and properties please check the official Bootstrap Documentation.