Story Map – tour – URL from page. Shows in editor but not on front end, unless it is served as HTTPS! You can change that in ArcGIS Online from your My Content page, on the Settings tab for the app.

Try same with shortcode:
[iframely]https://www.arcgis.com/apps/MapTour/index.html?appid=3e74e61911e0482faa816f8ebe04babf&webmap=da81faef035e4f62bcd7667cc46db4ba#
[/iframely]