put https://api.voucherify.io/v1/loyalties/:campaignId
Updates a loyalty program for the following fields: start_date, expiration_date, metadata, description, type, loyalty_card. Other fields won't be modified (even if provided they are silently skipped). Any parameters not provided will be left unchanged.
This method will update the loyalty cards (vouchers) which have not been published or redeemed yet.