Hezbollah fired a medium-range ballistic missile which was intercepted by David's Sling air defense system (designed to intercept medium-range missiles), not the Iron Dome.
The timing of this missile launch was especially significant. It was fired at 06:29, the same moment when the October 7th Operation started.
This attack caught the Israelis off guard because they had concluded that Tel Aviv was not involved at this stage.
https://en.irna.ir/news/85606986/What-do-we-know-about-Hezbollah-s-ballistic-missile-fired-at