Since you're using PLECS Blockset, Simulink handles the actual execution of the model, not PLECS. You would use the sim('model') call, as you have pointed out already.
The video you are referencing is for PLECS Standalone, where PLECS handles the execution of the model, and therefore has a different command to run the model.
You can still access the PLECS model, manipulate parameters, save scope captures, and so on through the PLECS API, and intermix these calls with MATLAB calls as needed.
Refer to the "Buck Converter with Parameter Sweep" demo model. It highlights the code used to run a parameter sweep for PLECS Blockset and Standalone.