prospect_email: This should be the email of the prospect you wish to add to an existing campaign.
other_fields: This should be an object(dictionary) of other attributes of this prospect like age, name, location. A combination of key/value pairs. These attributes are used in personalization.
verify_email: This verifies the prospect's email before adding them to a campaign if set to true and will skip verification if set to false. important to mention that the decision to send to prospect based on the verification status is made at the campaign level, during the campaign creation configuration.