Insert the options you need for your configuration.
Go to the "My account" settings, here you need to activate the domain(s) you want to use.
Now you can activate the Magento 1.x integration under "My account > Integrations".
Afterwards you will get a security token and a download for a Magento integration plugin.
Finally you need to link the configurator template to a simple product in the Magento catalog.
Under "Catalog > Custom Options > Input Type" you need to select the Product Configurator, afterwards you will get a dropdown to select the template you want to be linked.
Congratulations, you successfully created your first configuration!
Now go to your frontend and look at your work.