While you can use ScoutIQ 2 and ScoutIQ right away, with or without an Amazon Professional Seller account, these apps are designed for Amazon Pro-Sellers, and pairing your account with the apps is strongly recommended, since doing so will enable you to view personalized restriction checks.
These checks allow you to know whether or not you are gated by Amazon from selling a particular item and will need to apply for approval. ScoutIQ 2 also allows you to apply for approval directly in-app if your account is paired. As a result, connecting your Amazon account will help you make more informed purchasing decisions.
If you wish to pair your Amazon Professional Seller account, this visual step-by-step guide will walk you through the process.