Hi.
I have Poly phones registered in BYOC Cloud architecture, and use the Stand Alone license. Do not have a logged-in user. I do Transfer-To from Architect.
"ringing" and "pick-up" are participant states. You can get events when the conversation changes using the conversation topics.
In comparison to many other telephony platforms whereby users log into a phone and calls are assigned to the phone, there, the phone is a central entity in handling a conversation. In Genesys Cloud, all of those things are centric to the user. i.e the user logs in, the user assigns a station to themselves, the user is assigned calls ; the user is the central entity in handling a conversation. The phone is treated as a latent consideration of how to actually connect to the media path, but only as a result of connecting the conversation to the user.
Ultimately, If you want to know "when the call is ringing" and "when the call is picked up", you would look at the user's participant in conversation because the user is participating in the conversation, not the phone.