On Call series creator Elliot Wolf has explained whether Wolf Entertainment’s latest streaming series takes place in the shared One Chicago universe. The Prime Video series is the first from the production company to be a half-hour per episode, focused on officer Traci Harmon (Troian Bellisario) and rookie Alex Diaz (Brandon Larracuente) as they respond to calls in Long Beach, California. The procedural style is similar to other shows produced by the studio, including those that fall under the Law & Order, One Chicago and FBI umbrellas, created by Dick Wolf. These three franchises also connect in the same universe.

https://screenrant.com/on-call-one-chicago-universe-connection-elliot-wolf-response/