Select the Ellipsis (...) of the card that you want to created a Campaign for (Share your message with a Shuffle Campaign):

Select the "campaigns" option:                                                                                                                                                    

Select the Facebook messenger campaign that you have created:                                                                                                    

Select "Copy Link"                                                                                                                                                                                

Open your Facebook Messenger to the person/people you would like to share your  campaign with. Place link and you will see a preview. Please note, it may take some time for your thumbnail to populate.