Hosted IT Advisor users can be configured to use the Log in with EcoStruxure IT option to log in to ITA. This is the default for newly created/installed hosted ITA instances.
In IT Advisor, check the box in the user's properties to Force user to use Single Sign On.
Log in to EcoStruxure IT at https://app.ecostruxureit.com/manage. Click Administration and make sure the hosted ITA server is registered to an organization in EcoStruxure IT. This normally occurs during onboarding for hosted ITA.
Click Users to create an EcoStruxure IT account for the users you want to access ITA using SSO. The EcoStruxure IT account username must match the ITA username.