There are two main options. One is that you can "freeze" the tracks so the processed audio is saved to disk so then you don't need the plug-in. Many DAWs, such as Pro Tools, have a freeze function to do this automatically, or you could bus the output of Sphere to another track and record it. If you are using a Universal Audio Apollo you can also commit the output of Sphere by using "UAD REC" mode.
The other option is to ask the mixing engineer to install the Sphere plug-in. Anyone who registers on our website can download the native/HDX Sphere plug-in. This option allows the mixing engineer to choose mic types and other Sphere settings.