Fill out the URL. The Link Text should be filled out for you already
Check the box that says “Open link in a new window/tab”.
That’s it. When you click on the hyperlink in the content, it’ll take you to a new window or tab and will leave your content open in the previous location.
Internal Link Targeting
You want to make sure that people visiting an internal link (a link that shares a domain with your website url) don’t visit a new window or tab. It’s assumed that any links that are in the same domain are on the same site and shouldn’t confuse users. One exception: if you host multiple websites in sub-folders, and want to link from one site to another, use a new tab or window.
As a bonus, if the content you want to link to is a WordPress content piece (page, post, category, or custom content / taxonomy), you can click the “Or link to existing content” drop down and see options to easily link to existing content.