We can set the subject of email campaign with api
But how can we set the preview of email subject in campaign
e.g.
$emailCampaign['subject'] = "this is a subject"
$emailCampaign[''] = "this is a preview"
What key should we use here for preview in api
Nowhere its mentioned in docs

We can set the subject of email campaign with api
But how can we set the preview of email subject in campaign
e.g.
$emailCampaign['subject'] = "this is a subject"
$emailCampaign[''] = "this is a preview"
What key should we use here for preview in api
Nowhere its mentioned in docs