In order to add a new work to a new issue you have to follow a few steps outlined below.
First, it is important that all the authors for a given issue have been added as authors in the Users section of that issue before you start adding the works. It is good practice to add all the authors to the system—along with their bios and images—before you start adding the works. For details on how to do this see the tutorial here.
When adding a new work, go to Posts–>Add New Post and fill in the title of the work.
After you have added the title and the text, you will need to categorize the work in the proper genre (namely fiction, poetry, interview,etc.).
After that you will need to assign the post to the proper author (this is why the author should be added to WordPress before you add a work). It will default to you as the author until you select a new author.
Once you select the new author you need to be sure to add the custom field author_lastname wherein the value field needs to be the author’s last name for that particular work.
Be sure to click “Add Custom Field” button after you select author_lastname and add the last name in the value field.
Finally, scroll back up and and click the big blue “Publish” button to commit your work. If it does not show up in the Table of Contents for this issue chances are you did add the custom field of the last name (or that field contains a typo).