A company wants to manage access and permissions for its third-party software as a service...

 AWS IAM Identity Center (AWS Single Sign-On) is the AWS service that the company should use to meet the requirements of managing access and permissions for its third-party SaaS applications. AWS Single Sign-On is a cloud-based service that makes it easy to centrally manage single sign-on(SSO) access to multiple AWS accounts and business applications. You can use AWS Single Sign-On to enable your users to sign in to a user portal with their existing corporate credentials and access all of their assigned accounts and applications from one place4.