Setting width for an embeded element

[Lvivcenter]

Hi there, 

I was trying to embed the external Timeline JS element I've created (link) according to the instructions I could find here. 

However, it is impossible to adjust the embedded element's width. There is no such option:

Interestingly enough, when I try to embed the test link (https://timeline.knightlab.com/examples/user-interface/index.html) from the instructions it works fine and the width is adjustable:

Would someone be able to advise what is the reason behind it and what are the possible solutions? 

Thank you!

Taras