There are two ways to do it: the first one lets you do it for individual articles, & the second way lets you set up the entire campaign for future publishing.
To schedule individual articles, click on the Generated Article section, & under the Generated Article tab, click on the view button ( for the article of your choice). Once in the view mode, in the top right corner, you will find the publish/schedule button. Click on it to view the option for scheduling it for later. Choose the date & time and click on schedule.
To schedule multiple articles or enable the Blog Automation for future publishing, click on the Auto Blog section on your Abun Dashboard. There at the top you will find an option to create a new blog automation project; click on it. Choose your desired details & click on start automation.