Updating Contacts that Already Exist on Flashy
You may collect additional information about your Flashy contacts, such as birth dates or any other details, and then want to add it to the records on Flashy.
To do this you will first need to create a CSV file containing a unique identifier of the contacts you wish to update (this identifier will usually be the contacts' email addresses) and further columns with the information you wish to synchronize with relevant fields in Flashy.