add encryption key

compose.yml

@@ -80,6 +80,7 @@ services:
       PUID: ${PUID}
       PGID: ${PGID}
       TZ: ${TZ}
+      SETTINGS_ENCRYPTION_KEY: ${DUPLICATI_PASS}
       DUPLICATI__WEBSERVICE_PASSWORD: ${DUPLICATI_PASS}
     dns:
       - ${DNS_SERVER}