The WAP121 does not support Guest Network or the so-called Cisco Captive Portal. The only option is to configure a separate VLAN (VLAN to SSID mapping) for the guest network and assign a scheduler for that particular VLAN. This will allows configuring a rule with a specific time interval for VLAN (VAP) or radios to be operational. You can refer to section Scheduler in the administration guide for more detailed information: https://www.cisco.com/c/dam/en/us/td/docs/wireless/access_point/csbap/wap121/administration/guide/WAP121_321_AG_en.pdf
Regards,
Martin
Getting Started
Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: