Hello Lara,
This is mostly something that you would want to ask the Universal Robots team, as ROS generally relies on creators of robots to create interfaces that allow their robots to be controlled through ROS.
Fortunately, a quick search indicates that UR robots in general seem to have ROS support, with the repository here. Not the specific callout on that page that UR16e has only preliminary support, and is not feature-complete. Also note that they currently recommend to use ROS Melodic, though Noetic works too. ROS Toolbox makes use of Melodic in R2020b-R2021b, and Noetic in R2022a.
Once you have the robot set up and being controlled through the ROS interface, you can build the custom messages in MATLAB using rosgenmsg, connect to the ROS Master, and begin controlling the robot through the specified topics, services, and/or actions.
-Cam
