add-block command in MATLAB

I want to add blocks to MATLAB simulink model by command line. I used add_block command to add a Constant block to my model by following command and it worked

add_block('simulink/Sources/Constant','MyModel/ConstValue')

But when I try to add’Chart’ to my model by the following command,

add_block('stateflow/Chart','MyModel/Chart')

It causes an error:

Error due to multiple causes.
Caused by:
    Unable to load block diagram 'stateflow'
    There is no block named 'stateflow/Chart'

How should I sove this prblem ?

>Solution :

Solution ref: https://uk.mathworks.com/matlabcentral/answers/53920-how-to-add-a-stateflow-chart-in-an-existing-simulink-model-using-api

The source you need is sflib/Chart not stateflow/Chart

So the command is something like:

add_block('sflib/Chart','MyModel/Chart')