Update variables.adoc

Author: ujibang

docs/websocket/variables.adoc

@@ -36,7 +36,7 @@ In case of the change stream *mine* described in the link:/docs/mongodb-websocke
 
 `$var` in RESTHeart change streams can utilize dot notation to access nested properties. This allows you to specify a complex variable structure and reference its components for more flexible filtering.
 
-For example, if a client passes a variable as `avar={"options": {"name": "Andrea"}}`, you can access the nested property `name` using the dot notation within an aggregation stage, like this:
+For example, if a client passes a variable as `avars={"options": {"name": "Andrea"}}`, you can access the nested property `name` using the dot notation within an aggregation stage, like this:
 
 [source,json]
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