Hi WW ,
Thank you very much for your answer.
Unfortunatelly as I exposed in the previous message , there is no Meraki APs associated to this account at this site, so there is no Wireless menu entry at the Meraki Dashboard to configure redirection to another URL.
Wireless access and SSID profiles are configured at 3rd party Ubiquiti Unifi APs using a central management service. Unifi.
When a connection is initiated by a guest user , guest user associate to the Wifi in Openauthentication mode.
Reach the Meraki MX firewall , and then he would need to be redirected to the unifi guest portal. But there is no way to configure that in Meraki , cause it only support "Radius , FaceBook , and Google" as authentication sources.
Regards.-
Santi .-