On a technical level, this is a variable or keyname.
On an interface level, this is an inline button (that I suspect may also be some kind of dropdown / select menu, but I could be wrong).
On a graphic level, this is a pill, or rounded rectangle. While such elements don't always imply interactivity, shape is one of many common ways to set content apart visually, which is a key element in making interaction discoverable. The colors and borders also contribute. Here's a concise article on making click targets discoverable.