Keycloak 15.0.2: where can i register the 'frontchannel logout URL'?

in the keycloak document: Server Administration Guide, it state:

“This is also a browser-based logout. In contrast to the Session Managment based logout approach Keycloak will send logout requests to the clients. Applications or clients need to have a frontchannel logout URL registered at Keycloak. After triggering a logout at Keycloak, it will send logout requests to these registered URLs that will terminate the client sessions.”

but i am not able to see the ‘frontchannel logout URL’ in the admin console…i just see the ‘Backchannel Logout URL’ inputbox there…

can anybody give me hint about where i can find that setting?

thank you.