How do I show Interstitial Ads in a blueprint project on IOS?

I have not tried that plugin, so I can’t comment on how it compares. All I know is that at the time that I chose EasyAds Pro, the only other solution was an outrageously overpriced plugin that seemed to have a lot of issues (and apparently is no longer supported). EasyAds Pro is very well rated (see the reviews). But the short version is yes, you will need a plugin. There are some free solutions out there, but I do not know of any that don’t come with a whole host of complaints.