POST request will have the following data in its body:
Content Details Request
uniqueId and metadata properties will contain the values defined during
content import.
The expected response to this is a json object with the following format
Response

Content details
fields
This is used to create custom inputs on each breakdown row of a block. The value
of each input field is stored on the row, in its integration property under the
field’s id: row.integration[field.id] on a
Multi-Product Row.
A field’s defaultValue is written there when the row is created.
See IntegrationField for information on how to use them.
subResources
This is used to be able to add custom quick addable sub resources to a block (using the blue button with a plus icon). The format of this is as follows:
ContentSubrow
block.multi_product_data as a subrow.
customSubrows
Custom subrows are predefined subrows that will be added to block.multi_product_data automatically. These are usually
internal subrows that the user should not be able to modify. Therefore it can be good to set the
hideSubrows property to true when using it.