We've just rolled out a new feature in the Beta phase that allows you to whitelist the hosts where the Pipe embed code can be added. This is useful to prevent abuse from malicious users that could embed your generated Pipe embed code on other websites.
The whitelist can be set up at the environment level so that you can have specific whitelists for each of your environments that could be related to different websites.
Access the new Whitelisted hosts section by editing any of your environments and add the hosts you want to whitelist.
The list will be empty by default, meaning any host will be allowed.
For more information about this new feature, you can read the documentation.