Let’s do web session send me a private email

you will need to write a custom submit handler to handle to form submission. In the custom submit handler write your logic to handle the submissionThe following article should help youhttps://experienceleague.adobe.com/en/docs/experience-manager-learn/cloud-service/forms/custom-submit-headless-forms...

Is your form based on the share point backed form data model?the data.json is the data from the submitted formyou can extract the individual elements from the data.json and insert the same into your SP list

So you have a core component based AF and you want to make a post call to a servlet on the click of a button? 

https://experienceleague.adobe.com/en/docs/experience-manager-learn/cloud-service/forms/prefill-azure-storage/introduction This is for the cloud service, but will work for 6.5 as well

Is this on cloud or 6.5 version?

Can you please contact support for this?

Let me checkBTW which version of AEM forms are you on?

https://experienceleague.adobe.com/en/docs/experience-manager-learn/cloud-service/forms/developing-for-cloud-service/registering-servlet-using-resourcetype

In the documentation link that you are following, there is sample syntax to access field values does that not work for you?can you send us the form?