update the expression

Author: spagarwa

articles/data-factory/control-flow-expression-language-functions.md

@@ -60,7 +60,7 @@ Expressions can appear anywhere in a JSON string value and always result in anot
 
 > [!NOTE]
 > A complex example of how the parameters can be used is this, here to be able to use pipeline parameters in dot operator, '[]' is required.
-  activity('{activityName}').output.{Param1}.{Param2}[pipeline().parameters.Param3].{Param4}
+  @activity('{activityName}').output.{Param1}.{Param2}[pipeline().parameters.Param3].{Param4}
 
 ## Examples