Embedded program not appearing in web page.

I’ve been using Khan Academy to practice programming and when I’ve finished each important topic, I used the embed for that program to insert it into my GitHub webpage. Originally each one was viewable and able to be interacted with inside the page itself, but a few days ago they suddenly stopped.

Now the only thing that is shown are the links to each little program. I’ve not done anything to change the setup or mess with settings, so why did this just suddenly happen?

you mean this one ?

I’m just guessing,

and when you mean embed, just the code ? or a program running on your page ?