✏️ Fixes formula

Author: dej611

x-pack/plugins/lens/public/indexpattern_datasource/operations/definitions/formula/util.ts

@@ -730,7 +730,7 @@ Example: \`gte(average(bytes), 1000)\`
 Returns a value depending on whether the element of condition is true or false.
 
 Example: Average revenue per customer but in some cases customer id is not provided which counts as additional customer
-\`sum(total)/(cardinality(customer_id) + ifelse(count() > count(filter=customer_id:*), 1, 0))\`
+\`sum(total)/(unique_count(customer_id) + ifelse( count() > count(kql='customer_id:*'), 1, 0))\`
     `,
     }),
   },