Bootstrap Dropdown not Displayed Properly with Latest Version

I’m working on a right-click Bootstrap menu, the script I’m using is developed for Bootstrap 3.3.5, while on my website I’m using Bootstrap 5.2.3,

Here is the script I’m trying to use: https://github.com/dgoguerra/bootstrap-menu

Now the dropdown menu doesn’t look the same on the demo page of the script and on my website, so I edited the demo page to use the same version (Bootstrap 5.2.3) as my wesite, and the demo changed to look like on my website which is not what I want.

Here is the comparison between the two:

The demo page is using only Bootstrap CSS (without JS)

Now what have changed in Bootstrap for the dropdown and how can I fix the script to adapt to the latest Bootstrap version?

Here is the uncompressed script: https://wecamp.tn/BootstrapMenu.js

Here is the demo main code:

<div id="demo1Box" class="text-center" style="height: 300px; border:1px solid #ddd">
    <span style="line-height: 300px">Right click anywhere inside this box</span>
</div>

<script>
    var menu = new BootstrapMenu('#demo1Box', {
        menuEvent: 'right-click',
        actions: [{
            name: 'Action',
            onClick: function() {
                toastr.info("'Action' clicked!");
            }
        }, {
            name: 'Another action',
            onClick: function() {
                toastr.info("'Another action' clicked!");
            }
        }, {
            name: 'A third action',
            onClick: function() {
                toastr.info("'A third action' clicked!");
            }
        }]
    });

Any help would be welcome. Thanks in advance!