Hi Sophia,
You can export the Simscape model as an FMU as long as the input and output signals are in the form of Simulink signals instead of physical signals. The PS-Simulink Converter block can be used to convert physical signals to Simulink signals. You can refer to the following MATLAB Answer, which has information regarding exporting FMUs with physical connections: https://www.mathworks.com/matlabcentral/answers/2023122-can-i-generate-an-fmu-where-the-i-os-for-the-model-connect-to-simscape-physical-connections.
The Connection Port block in Simscape is typically used for physical connections. It is similar to the Inport and Outport blocks in function, but I do not think it can be used as a second output in the model as it transfers the physical connection across subsystem boundaries. You can look into the documentation of the Connection Port block for more information: https://www.mathworks.com/help/simscape/ref/connectionport.html.
I recommend using the PS-Simulink Converter block to convert the signal to a Simulink signal, and an Outport block can be attached to have a second output.
I hope this information helps you!