Antigravity is defined as an area which is free from gravity. If it existed, antigravity could make objects weightless or be used to propel spacecraft. Creating antigravity would mean shielding an area or a device from gravitational forces.
According to general relativity, where gravity is the result of the geometry of space-time, this would simply be impossible. According to quantum theory, hypothetical particles called gravitons transmit gravitational forces.
But given that we do not even know if these particles exist, destroying or controlling them seems more or less impossible. For now, scientists are therefore dubious that antigravity will ever exist anywhere but in the imaginations of science-fiction fans.