This method selects vouchers that are suitable for publication, adds a publish entry and returns the publication.
A voucher is suitable for publication when it's active and hasn't been published yet.
Clearly define the source of the voucher
You must clearly define which source you want to publish voucher code from. It can be either a code from a campaign or a specific voucher identified by code.
Publish multiple vouchers
In case you want to publish multiple vouchers within single publication you need to specify campaign name and number of vouchers you want to publish.
In case you want to ensure the number of publishable codes increases automatically with the number of customers, you should use auto-update campaign.
Returns a publication object if a valid identifier was provided. Object will contain single published voucher object or list of published voucher codes in case of multiple publication.