My Settings for Power BI integration (web portal)
Applies to: 
SQL Server 2016 (13.x) Reporting Services and later
Power BI Report Server
The My Settings page in the Reporting Services web portal is used by individual users to manage their sign-in with Power BI. When you go through the steps to pin a report item, you automatically see a prompt to sign. However, you can use the My Settings page if you need to manually sign in or if you need to sign out. If the My Settings menu option isn't visible, the report server isn't integrated with Power BI. For more information, see Power BI report server integration (Configuration Manager).
Why sign in
When you sign in, you establish a relationship between your Reporting Services user account and your Power BI account. The sign-in creates a security token that is good for 90 days. If the token expires, and you have items pinned to Power BI, you see a notification.
Tiles within Power BI dashboards don't refresh until you sign in again through MySettings.
Once you sign in, you receive a new security token. Your dashboard tiles begin updating on their previously configured schedules.