Dropbox JavaScript SDK vs Dropbox saver JavaScript

These libraries weren't written with each other in mind unfortunately, but you can do something like this to work around it:

    <script src="https://www.dropbox.com/static/api/2/dropins.js" id="dropboxjs" data-app-key="riqoimk2j9c8d1m" ></script>
    <script type="text/javascript">
        var Dropbox_Dropins = Dropbox;
    </script>

    <script src="https://unpkg.com/dropbox/dist/Dropbox-sdk.min.js" ></script>
    <script type="text/javascript">
        var Dropbox_SDK = Dropbox;
    </script>

And then you can use Dropbox_Dropins or Dropbox_SDK in place of Dropbox respectively.