In this page you can find the walkthrough for Speak with January main mission found in Prey. This is one of the missions from the main story and you get it after watching the rest of the recording in Yu's office. The mission itself is very short and serves as an introduction for the trip to a new large location on the station - Psychotronics.
Since January is not a living creature you should not expect her to appear in Yu's Office in Talos I Lobby personally. Instead, an operator, that January took over, will appear there. Speak with her. You receive new objectives and a General Access card which can help you to get to a new part of the station and a neuromod.
When January appears in the room you can act in a different way - you can destroy the operator controlled by her. This action is required to get Suicide by Proxy achievement. What is interesting is that this action won't make you fail any of the upcoming main missions. You can examine the remains of the destroyed operator. Thanks to that you get a note (tips on what you should do next), General Access card and a neuromod.
In both cases a new main mission will begin, called Detour.