Use your Apple trackpad to middle click.
Choose from four trackpad gestures: click with three fingers, tap with three fingers, tap with four fingers, and Force Touch with one finger.
Or, hold the function key (fn) and left click with any mouse input device to perform a middle click.
Open links in new tabs, close tabs more easily by middle clicking on them, and easily paste text in the Terminal.
Try it out for free with an unlimited trial. Purchase within the app to close the trial window.
Note that MiddleTouch requires accessibility privileges to function.