do you have any instructions or information on how to set up Cisco SPA504G phones to work with FlyNumber pbx?
Thanks for posting and it should be pretty standard using the default settings. Using the domain, user and password provided by the PBX panel.
Could you post a screenshot of the settings screen for the Cisco phone?
It’s usually accessible when visiting the IP of the phone using a browser, if you need more guidance with that let me know
Thanks and standing by