The direct links to alert pages in the SCOM web console vary from version to version. The below describes the URL formats. Replace <Alert GUID> with the GUID to the alert.
SCOM 2012 (R2)
http://server/OperationsManager/#/web(url='/monitoringview/default.aspx?DisplayMode=Pivot&AlertID=<Alert GUID>')
SCOM 2016
http://server/MonitoringView/default.aspx/#/web(url='/OperationsManager/default.aspx?DisplayMode=Pivot&AlertID=<Alert GUID>')
SCOM 1801
http://server/OperationsManager/#/monitoring/drilldown/alert/<Alert GUID>