If we discard all sorts of fantastic artificial gravity generators, then there is one way – to use centrifugal force, realizing the rotation of a segment of the ship, or even the entire ship. However, the gravity there will be somewhat strange – local at each point, i.e. crew members will be able to walk freely on the walls and ceiling (from the point of view of other crew members), and this gravity will spread only to the rotating part. Well, in order for it to work, you need a person to start rotating with this section.
