Passing custom values in service saveconfiguration

Hello gurus,

I'm developing a CX app and, beyond product metadata,

On the service configuration form, we need to provide a few manually entered values (please check the screenshot).

I can read the product metadata and, eventually, we are able to send and receive the required DTO (input and output parameters), save the values in the tracking variable and access it within the program, but I don't know how to handle the extra fields.

What would be the best approach to this matter if you could help me?

In other words, how do we send the manual input values with the product metadata?