I am running a simulink model via matlab script using sim command, the issue is i want to give 3 inputs and take out 3 outputs from the model, and use those outputs in later lines in matlab script, but unable to take outputs using To workspace tool

I am running a simulink model via matlab script using sim command, the issue is i want to give 3 inputs and take out 3 outputs from the model, and use those outputs in later lines in matlab script, but unable to take outputs using To workspace tool, shows error as follows-

Error using main1 (line 4)

External input specified in the Configuration Parameters dialog box on the

Data Import/Export page (or as an option to SIM command) to a model

containing no root level input ports