You are sending request to their servers, they will save at least your IP request there.
There is no need to do that. You can just download the font and use it in your own server.
No offence, but to me, this sounds a little paranoid, doesn’t it? I mean, we talking here about font style. I am not sure is it possible to be 100% safe over the internet if you use all of his resources.
It can easily change an IP address, restarting router. Maybe I am naive, but I really don't see a serious problem here.
But in this case there is no reason to get the fonts from their servers, and it is like 1kb file, why don't you host it?
It may be paranoid, but it is more a matter of philosophy about the web imo.
..
You just need this code:
<div class="dropdown">
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css" integrity="sha384-JcKb8q3iqJ61gNV9KGb8thSsNjpSL0n8PARn9HuZOnIxN0hoP+VmmDGMN5t9UJ0Z" crossorigin="anonymous">
<script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" integrity="sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj" crossorigin="anonymous"></script>
<script src="https://getbootstrap.com/docs/4.5/dist/js/bootstrap.bundle.min.js" integrity="sha384-LtrjvnR4Twt/qOuYxE721u19sVFLVSA4hf/rRt6PrZTmiPltdZcI7q7PXQBYTKyf" crossorigin="anonymous">
Now you here linking to
bootstrapcdn.com jquery.com and
getbootstrap.com. here is also a problem
But this is just to make the fiddle work. I just said that he should download the files and run in his server.
You just have to load the dependencies libraries (jquery, bootstrap css and bootstrapbundle.js, then download them to your /css or /js directories).
See a working example, which you can edit.
-snip-