Hubspot Tracking via JS

I’m trying to use the following hubspot tracking embed code:
Start of HubSpot Embed Code -->
script type=“text/javascript” id=“hs-script-loader” async defer src="//">
!-- End of HubSpot Embed Code -->
…as a plugin for a prototype, but tracking appears to be getting blocked or prevented from loading? Does anyone know if I’m doing something wrong or if Axure Cloud automatically blocks this sort of tracking methodology? (I know the code is missing some <'s - was just trying to get it to show up here)