Create custom form fields that show up under Form Submission Details

Hi, I’ve created a Webform with some custom code and custom form fields and I just want them to show up on the product form submission. I honestly don’t even care if about the information showing up under a customer’s profile on Max Classic, the only thing I need it to really show up is on the actual Form Submission Details when I click one of these form links shown here:

Here is a picture of what my custom code looks like for the one of the fields: Screenshot - fd4697fae03894494b976124da48bb0f - Gyazo

I normally would create a custom field on Keap and make it on the webform builder in the campaign builder, however this form field I am generating using javascript by duplicating a field with a button creating multiple fields with the same under 1 id, but class names like inf_custom_SerialNumber_2, inf_custom_SerialNumber3, inf_custom_SerialNumber4, going incrementally, so creating a bunch of custom fields would be a pain and inefficient.