Unfortunately Microsoft Edge doesn't allow custom clippers (like the Add to DesignFiles button) to be dragged and dropped to the bookmarks bar.
We would recommend jumping over to a different browser like Google Chrome, Firefox or Safari.
Here's the Google Chrome download link: https://www.google.com/chrome/
Once downloaded, please retry the browser clipper installation process found here:
If you have any other questions, please reach out via the chat bubble in the bottom right corner. We'd be happy to help!