diff --git a/services/aggregatorUsageEvents/ecolyo.js b/services/aggregatorUsageEvents/ecolyo.js
index 34008c273f7a03f01905f8f2fbfd4b01321f6158..028ef99a91ec301cf6dd193910c1eaf34bbccbd7 100644
--- a/services/aggregatorUsageEvents/ecolyo.js
+++ b/services/aggregatorUsageEvents/ecolyo.js
@@ -322,6 +322,9 @@ const calculPeriodBetweenFirstConnectionAndFirstChallenge = async (events, first
       // eslint-disable-next-line @typescript-eslint/camelcase
       group2: {
         end_event: 'first_challenge'
+      },
+      group3: {
+        params: ''
       }
     };
     const result = await sendIndicator(periodIndicator, client);