It is as simple as using the HTML Widget and replacing trumpet's URL below with your chosen website:
Copy and paste this snippet
<iframe src="https://www.sendtrumpet.com" height="600px" width="100%" title="description"></iframe>
Please note:
The Preview of the website fails with the error example.website.com refused to connect
Review the console in the browser with Developer Tools (Ctrl+Shift+i)
Under the Network logs, please check x-frame-options. If it is DENY, the page cannot be displayed in a frame