diff --git a/apps/onboarding-functions/src/main/java/it/pagopa/selfcare/onboarding/client/auth/AuthenticationPropagationHeadersFactory.java b/apps/onboarding-functions/src/main/java/it/pagopa/selfcare/onboarding/client/auth/AuthenticationPropagationHeadersFactory.java
index ddc34b09e..a16966275 100644
--- a/apps/onboarding-functions/src/main/java/it/pagopa/selfcare/onboarding/client/auth/AuthenticationPropagationHeadersFactory.java
+++ b/apps/onboarding-functions/src/main/java/it/pagopa/selfcare/onboarding/client/auth/AuthenticationPropagationHeadersFactory.java
@@ -22,6 +22,7 @@ public class AuthenticationPropagationHeadersFactory implements ClientHeadersFac
     @Override
     public MultivaluedMap<String, String> update(MultivaluedMap<String, String> incomingHeaders, MultivaluedMap<String, String> clientOutgoingHeaders) {
         String bearerToken;
+        // If user is founded on PDV, a bearer token is created starting from it
         if (!clientOutgoingHeaders.isEmpty() && clientOutgoingHeaders.containsKey(USER_ID_HEADER)) {
             final String uuid = clientOutgoingHeaders.get(USER_ID_HEADER).get(0);
             final String jwt = tokenService.createJwt(uuid);
diff --git a/apps/onboarding-functions/src/main/java/it/pagopa/selfcare/onboarding/service/CompletionServiceDefault.java b/apps/onboarding-functions/src/main/java/it/pagopa/selfcare/onboarding/service/CompletionServiceDefault.java
index c3beaf024..43c8809b3 100644
--- a/apps/onboarding-functions/src/main/java/it/pagopa/selfcare/onboarding/service/CompletionServiceDefault.java
+++ b/apps/onboarding-functions/src/main/java/it/pagopa/selfcare/onboarding/service/CompletionServiceDefault.java
@@ -176,6 +176,10 @@ public void persistUsers(Onboarding onboarding) {
             userRoleDto.setUserMailUuid(user.getUserMailUuid());
             userRoleDto.setProduct(productMapper.toProduct(onboarding, user));
             userRoleDto.getProduct().setTokenId(onboarding.getId());
+            /*
+              The second parameter (header param) of the following method is used to build a bearer token with which invoke the API
+              {@link it.pagopa.selfcare.onboarding.client.auth.AuthenticationPropagationHeadersFactory}
+             */
             try (Response response = userApi.usersUserIdPost(user.getId(), onboarding.getUserRequestUid(), userRoleDto)) {
                 if (!SUCCESSFUL.equals(response.getStatusInfo().getFamily())) {
                     throw new GenericOnboardingException("Impossible to create or update role for user with ID: " + user.getId());