Members of your organization can access the ArcGIS Enterprise Sites application by signing in to your organization's ArcGIS Enterprise with their ArcGIS Enterprise account.
-           Open the URL for your organization's  portal website.Note:You can also access the Enterprise Sites Overview using the URL https://webadaptorhost.domain.com/webadaptorname/apps/sites/#/home/overview/edit. 
- Select Sign in at the top of the website home page and enter your account credentials.
- Select the apps switcher button    next to your user profile and choose Sites. next to your user profile and choose Sites.