Add custom element whitout shape inside bpmn:Process

I’m trying to add one or more elements inside the bpmn:Process. However, the element to be added does not have a geometric shape, but is only a useful element for the logic of the project. The element is defined as “custom:Product”.
The addition or removal must occur in the output xml file and must be able to be read when the file is imported.

The output I would like to have is like this:

<bpmn:process id="Process_03dsped" isExecutable="true">
    <bpmn:startEvent id="Event_1w8pvk8">
    <custom:product id="Product_ci399a" name="Product_1"/>
    <custom:product id="Product_jne129" name="Product_2"/>

Cool. Do you have a question or did you just want to share your project?

It would be a question. I would like to know how to add the custom:Product element inside the bpmn:Process file from code