Why does Postman "form-data" body send differently than "raw>JSON" body?

Question

When I make a simple POST to my local intake endpoint, I can create a lead with the following very simple raw JSON body inside Postman:

{
    "identification_first_name": "New",
    "identification_last_name": "Lead",
    "identification_email_address": "new-intake2@email.com"
}

Now, I need to move my testing to use the "form-data" fields inside Postman as I need to test receiving a file, but when I copy over the exact fields into this form-data table, and add a file row, the endpoint does not receive anything. Why would it not just send these values in the exact same way that the RAW body does?

I would think just copying over the exact fields and values I am using in the RAW would work the exact same way? Even if I just remove the new file field and send the exact same fields with the exact same values it still doesn't receive the body. The API calls fine but the keys and values don't get passed into the request, it's just blank.

Do I need to prefix or change the references in the form-data section compared to raw>body? Or is Postman adding some different layering to this body so my API needs to adjust where it's looking, sending inside an extra array or object?

Thanks!