To store the result of what your customer has configured in Printess you can simply call
printess.saveJson(). In return you will get a token that yu can easily use to load this state if the customer returns or want to make changes. You also can use this token to load the customers design e.g. in your support portal to apply fixes you might have received via email or phone.
Save customers work
const myToken = await printess.saveJson();
Load customers work
To test it, we added a button in the toolbar Save State, which saves the current state and returns a token to load it later. Just try it, make some other changes or even load a different template, and then press Load Stated, paste the token to the prompt and you will see the state you prevoiusly stored.