you can this snippet to give scroll able container code in the context area of the widget.
You can use the data widgets and give the widget width and height according to your need or change the row limit values. it’ll act as an scroll able container
is it really an iframe what you are looking for? iframes are typically used to display content of other webpages within your pages.
If you are just looking for a solution to show your application content like data or text in one page, you might be looking for a css solution instead; you could set the width and or height of your container to a fixed size and set the overflow to auto. https://css-tricks.com/almanac/properties/o/overflow/