TestResults.io has two tabs which are available from the TestResults.io extension menu. Each tab is responsible for a different function:
Test Environments tab - allows you to connect to the Subject Under Test (SUT)
Image Explorer tab - allows you to view the images you have taken while working with the Designer
If you want to access either of them simply select them from the TestResults.io top menu (Visual Studio 2017) or from the Extensions-->TestResults.io menu (Visual Studio 2019).
The first tab you will need to use is the Test Environment tab where you will enter the data of the env. against which you will develop your SW Model/Test Cases.