Hi,
This depends on the alert type. Also if it is Log alert depends on how it is configured. You can find more information on common alert schema. If it is a metric alert property alertTargetIDs contains the resource ID of the resource. If it is Log Alert v2 the alert needs to be configured with dimension _ResourceId and the dimension and its value will appear in alertContext.condition.allOf[0].dimensions[x].value where x is the number of the dimension for _ResourceId. You could configure another column for dimension if you want but in Azure it is best to work with Resource IDs as those are unique even if you have for some reason two servers with the same name.
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