Thanks for the answer. Being able to change backups interval will do the trick.
So this option will not be available for AEP users.
Though I have another problem (even to change network key, etc):
First, I edit the file /var/config/lora/lora-network-server.conf and save it.
Then I restart the LoRa Network server (/etc/init.d/lora-network-server restart).
After the reboot the file as been restored with original parameters, so the network does not apply changes.
The only way i was able to do effective changes is only with Web interface. There is a lot of parameters that are not available through this interface.
Is there any command/parameters to change allowing the configuration with the file instead of the web interface ? Or is it an issue ?