There are actually two ways of sharing article content with future issues. You should start by figuring out how you want this article to behave.
Option 1 creates that article in every issue you create. This is useful if the article should always stay the same or you don't mind that any changes you make to it would go into affect even for previously posted pages.
Option 2 simply allows you to create a copy of a previously existing article. This option is more of a copy and paste. It simply creates a copy of the article into the current issue. Any changes you make this way only affects the issue you are currently in. This is useful if you have previous articles you would like to use but you want to make changes and not affect a previous version.