Add multi-body gravity

Would you download KSP because you can't find Lagrangian points? Do you use Multibody Gravity Module in KSP? Change the gravitational range of each planet to infinite. And every celestial body and every spacecraft is affected by any celestial body.
Use four reference modes in the map.Surface,Planet center,Orbiting other planets and the center of gravity of planets surrounded by other planets(For example, when choosing the earth, refer to the center of gravity of the earth and the sun),Orbiting planes around other planets and planets surrounded by other planets.(For example, when choosing the earth, use the surrounded plane of the earth around the center of the sun as a relative reference,One of the directions of the reference line axis is always facing the sun)