I do not think this is possible on the phone
You can use 3CX client and webclient to see who is logged into a queue
https://www.3cx.com/docs/pbx-queue-status/
https://www.3cx.com/user-manual/web-client/
Hello @epress
Please note that it is not possible to monitor the login/logout status of an extension through the BLF keys of an IP phone. Only the 3CX clients have the ability to do so as this is done only through presence.
Founded in 2005, when VoIP was an emerging technology, 3CX has gone on to establish itself as a global leader in business communications.