iZotope products can be easily authorized via Product Portal. You can see full authorization methods broken down for them in this article.
Exponential Audio products have a separate authorization process through iLok, this can be seen in this article.
Most of the products sold by iZotope are not Standalone applications. These require a host application to run. Be sure to check individual product specification pages for compatibility, you can see DAW-specific setup steps in this section.