To move your database from cnMaestro Cloud to cnMaestro On-Premises, please contact Cambium's Customer Support. Within approximately 48 hours, you will be sent a link where you can download your cnMaestro cloud database into your On-Premises setup.
Afterwards, you will need to configure the cnMaestro URL on your devices to point to your local cnMaestro On-Premises rather than the default, https://cloud.cambiumnetworks.com/