Run import sample data function upon theme activation

I am using the FrankM1/radium-one-click-demo-install script to import sample data. It works perfectly!

I would really like to run this script upon theme activation. This is for a WP multisite that will only have a single theme available to the sub sites so there will be no re-activating once the subsite is created. What would be the correct function call? Please and thank you.