Web app integration (popup type): why is my content loading within an iframe?

I have a webapp integration (popup type). When sending html to the client-side it loads it into an iframe. I saw some integrations (notably gmail integration), that manages to bypass this limitation. Not only does the popup from the gmail integration NOT load into a designated box iframe but the URL that shows up at the top of the popup is the actual gmail url. (Not the box url.)

I was wondering how I could bypass this for me own app. When I try to do a redirect from my own client-side code (within the iframe) it redirects only within the iframe with the iframe still existing as the parent. (This causes issues in my app as the link I want to redirect to has the same-origin parent-frame policy)

Any help would be greatly appreciated.