The indigenous OTV brings together two significant and unprecedented developments. FGN-TUG-S01, Türkiye’s first-ever orbital transfer vehicle, is powered by the world’s first-ever hybrid rocket engine. Upon successfully entering mission orbit, it will ignite its hybrid engine for the first time as planned. This maneuver will be the first-ever orbital ignition of the hybrid rocket engine in both Turkish and global space history. The indigenous OTV will, thanks to its safe and low-cost hybrid propulsion system, make it possible for satellites to be transported to different orbits, prolonging their mission life.



It is difficult to parse the translations but I am confident they intend to refer to a “hybrid-propellant rocket engine” which indeed makes this a major milestone in rocketry in terms of orbital maneuvering engines.
https://en.wikipedia.org/wiki/Hybrid-propellant_rocket