fix display name for all subscribed_by

handlers/application/agenda.go

@@ -227,13 +227,13 @@ func (h *ApplicationHandler) AgendaSubscribeEvent(w http.ResponseWriter, r *http
 		w.WriteHeader(http.StatusBadRequest)
 		return
 	}
-
+	dis := fmt.Sprint(current_user_claims["first_name"]) + " " + fmt.Sprint(current_user_claims["last_name"])
 	subscriber := r.FormValue("subscriber")
 	data := map[string]any{
 		"subscribed_by": map[string]any{
 			"user": map[string]any{
 				"id":           current_user_token.Subject,
-				"display_name": current_user_claims["display_name"],
+				"display_name": dis,
 			},
 			"group": map[string]any{
 				"id":   current_group.ID,