I am struggling with what seems like a relatively basic function in my Story Map and it's something I've successfully done in the past with Classic Story Maps. I simply want to embed a webpage (a take action page where a user fills in their contact info to sign a petition) at the end of my Story Map. I've generated the iframe code and tested it and it seems to be working correctly, however Story Maps will only let me add it as a card, not interactive content. I'm having no trouble embedding videos (Vimeo, YouTube work fine) but I can't seem to embed this webpage. I've tested it with other web pages and it doesn't work for them either. The page I want to embed is an https site (not http) so I don't think it's that. When I embed a video I'm given all sorts of formatting options, including the interactive content feature. When I embed a webpage it only defaults to creating a card and interactive content is disabled.
What am I missing?
I encountered a similar-sounding problem some time ago. If I recall correctly, I was able to resolve the issue by adjusting the X-FRAME-OPTIONS settings in my website's firewall. Those settings can block embedding by external sites.