There is only about one means of speed of light interstellar communications with enough power to overcome interference to send messages across such vast distances.
It is called a stellar Aldis lamp. An Aldis lamp is a “shutter lamp” used by ships at sea to silently communicate with each other.
By creating a much larger version in space, between the local star and the target star, that by applying a small current will change from transparent to opaque, simple code messages can be sent one way.
If we created such a lamp, it would likely be between the orbit of Mars and the orbit of Earth. Aiming it would be difficult, because it would have to stay between our Sun and where that target star system was going to be.
It would have to be kind of large wouldn’t it? I.e. about 864,000 miles in diameter to completely obscure the sun. Smaller if you’re will to settle for just dimming it somewhat.