Try this solution. I think this code solve your problem
**Bootstrap Model**
<!-- begin snippet: js hide: false console: true babel: false -->
<!-- language: lang-html -->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"></script>
<div class="wrapper">
<div class="container">
<!-- Button trigger modal -->
<button
type="button"
class="btn btn-primary"
data-toggle="modal"
data-target="#exampleModal"
>
Launch demo modal
</button>
<!-- Modal -->
<div
class="modal fade"
id="exampleModal"
tabindex="-1"
role="dialog"
aria-labelledby="exampleModalLabel"
aria-hidden="true"
>
<div class="modal-dialog" role="document">
<div class="modal-content">
<div class="modal-header">
<h5 class="modal-title" id="exampleModalLabel">Modal title</h5>
<button
type="button"
class="close"
data-dismiss="modal"
aria-label="Close"
>
<span aria-hidden="true">×</span>
</button>
</div>
<div class="modal-body">
<iframe
src="https://getbootstrap.com/"
name="myIframe"
class="w-100 h-100"
></iframe>
</div>
<div class="modal-footer">
<button
type="button"
class="btn btn-secondary"
data-dismiss="modal"
>
Close
</button>
<button type="button" class="btn btn-primary">Save changes</button>
</div>
</div>
</div>
</div>
</div>
</div>
<!-- end snippet -->
### For Bootstrap 4 stable:
Since beta Bootstrap 4 doesn't depend on Tether but **Popper.js**. All scripts (**must be** in this order):
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/umd/popper.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
See the current [documentation][1] for the newest script versions.
---
### Only Bootstrap 4 alpha:
Bootstrap 4 **alpha** needs [Tether][2], so you need to include `tether.min.js` **before** you include `bootstrap.min.js`, eg.
<script src="https://npmcdn.com/tether@1.2.4/dist/js/tether.min.js"></script>
<script src="https://npmcdn.com/bootstrap@4.0.0-alpha.5/dist/js/bootstrap.min.js"></script>
[1]: https://getbootstrap.com/docs/4.1/getting-started/introduction/#js
[2]: http://tether.io/
