At present, there is no known method to produce anti-gravity or manipulate gravity in a way that counteracts the attractive nature of gravity as described by general relativity. Gravity is a fundamental force in the universe that attracts masses towards each other, and it is well-described by Einstein's theory of general relativity.
While we have developed technologies that can generate forces that counteract or overcome gravity in specific situations (such as levitating objects using magnetic fields), these methods do not negate or reverse the gravitational force itself. They rely on other forces to counterbalance or overcome gravity locally.
The idea of anti-gravity often appears in science fiction, where hypothetical technologies are depicted that allow objects to repel or counteract gravity entirely. However, such concepts remain speculative and are not currently supported by scientific evidence or established theories.
That being said, scientific research continues to explore the fundamental nature of gravity, and new insights and discoveries may potentially lead to a better understanding of gravity manipulation in the future. But as of now, producing anti-gravity or counteracting gravity in a practical and controlled manner remains beyond our current technological capabilities and understanding of the laws of physics.