It doesn’t work because the iframe references diglife. coop, and that server is configured to send a
X-Frame-Options: ALLOW-FROM https://diglife. coop HTTP header, which suggests to the client that the server doesn’t want its content iframed via other hosts other than itself, and diglife. com that does the iframing is obviously another server than diglife. coop itself, resulting in a “Load denied by X-Frame-Options: https://diglife. coop/ does not permit framing by https://diglife. com/iframe-test/.” message in the console.
By the way, note that at this point the web/browser (their vendors) conspire against you as the user, as the server can’t have any clue if the request is from an iframe or a regular visitor of the target site, so the browser vendor is conspiring against you to enforce the interest of server operators against the interests of the user, with this kind of non-technical, anti-digital pseudo fake pretense that on the real technical level could just be ignored.
By the way, why can’t I put more than two links in a post? What sort of place is this? I’m only citing anyway, your very own stuff! I recommend to get rid of this nonsense, or I see no reason why I should share/contribute good links here.