Please fine the below steps to full-fill the client requirement.
To add new article in Replication
SSMS à Replication à Local Publications à right click on your publication à Properties à Click on 'Articles'
tab à Uncheck 'Show only checked articles in the list'.
To verify added new article-
SSMS à Replication à Local Publications à right click on your publication à Properties à Click on 'View
Snapshot Agent Status' à Click on 'Start'
à It will show how many articles generated. If you
added one new article to it will show N+1 article.
Note: - N (existing article) + 1 (New Article)
Please comment below if you know any other way to add new article in Replciation. - Jainendra Verma