How to Create a Website (Avoiding Sandboxed Iframes)

For reasons I do not understand, Google Sites uses sandboxed iframes which prevents video recording on their site (see here).

Is there a way to create an html code that kicks the user out of Google Sites temporarily/redirects the user in a way to run HTML code that allows video recording features? If so, how would you do that?

Or is there a free website builder that is less restrictive and allows this to work?

Any help would be greatly appreciated!