This feature is part of an update currently being rolled out in eSign Online. If this setting is not available to you, it has not been activated for your account just yet. You can read more about this launch here.
The setting Enable form displays a form for the recipient party to fill in any remaining fields of information before proceeding to signing the document. You can find this setting under the Settings tab by scrolling down to Signing page settings > Enable form.
If you choose to to keep Enable form disabled, the signing experience will remain to be the same as before. The signing party scroll through the document to which they have been invited, and populate any fields that are marked as mandatory throughout the document.
By activating the setting Enable form, all fields will be summarised on a form page which is displayed to the receiving party before they are directed to the actual document. On the form page, the party can fill in all required information and then proceed to view the document which is to be signed. By doing this, the signing experience becomes easier for the receiving party and is especially helpful when there is an extended amount of information that you need to collect. See example below:
All fields under the tab Parties will be included in the form, which in turn will be logged in the Evidence Packade of the sealed document. If you would like the fields to be displayed inside the main document as well, add the fields to the document under the Document tab. If you add the fields visually in the document, they will appear as already populated for the receiving party once they proceed to view the document after filling out the form.
Not quite sure on how to work with and add fields to a document? Read more here.