post https://{region}-api.dotdigital.com/v2/address-books//contacts/delete-all
Deletes all contacts from a given address book
This operation can be used to delete all contacts from a given address book in your account.
The result returned will be a 202 Accepted message. You can use the id returned in the response to check the status of your request by calling Get bulk contact deletion progress
The id returned in the response can be used to check the status of your request by calling Get bulk contact deletion progress
Only can be used with custom address books!
It can't be used to delete contacts in All Contacts or Test address books.