Access to the Brainstorm Codes

Please carefully read the Brainstorm scripting page. It contains the answer to that question:
https://neuroimage.usc.edu/brainstorm/Tutorials/Scripting#Reference:_Display_functions

Moreover, you can see the .m script that reproduces the introduction tutorials ("Get started") here:
https://neuroimage.usc.edu/brainstorm/Tutorials/Scripting#Final_scripts