Getting Zoho Sign fields for CRM

Using Zoho Sign with a custom module, so can't use the extension. Use a webhook and Flow to send the sign doc with the default value of the fields set.

When a document is signed, I want to check the completed fields in the signed document against the CRM fields. Seems relatively straight forward.... apart from my deluge skills just aren't quite good enough.

I can get the data using zoho.sign.getDocumentByID. I can see the data I want, but I don't seem to have the skills yet to extract the field name, default values and actual values. I've tried all sorts of .get() to grab it, but I am .get()ting nowhere fast. Please can someone point me in the right direction?