iframe sizing

hi everyone, 

I'm inserting an e-learning storyline into a page on the website and I've used this coding:

<center>
<iframe src="https://www.walkgroveonline.com/Probation_Institute/2020_Updates/Direct_Link/story.html" style="border:0px #ffffff none;" name="myiFrame" scrolling="no" frameborder="1" marginheight="0px" marginwidth="0px" height="400px" width="100%" allowfullscreen>
}</iframe></center>

Is there some custom way of allowing this to be made full page by the user or at the very least a way of me increasing it to fill the page more? 

Many thanks.

Can you share link to page where you inserted above code?

Hi @tuanphan

Link https://oarfish-salmon-gpgd.squarespace.com/veterans

Password: criminaljustice

Hi @tuanphan did you manage to look at this? 
many thanks. 

div#block-yui_3_17_2_1_1590447283629_4347 {
    width: 100% !important;
    max-width: 100% !important;
    margin: 0 !important;
}

As always, huge thank you @tuanphan 🙂