New "gravity force" analogous to magnetic force?

I was watching Eugene Khutoryansky's physics video about Einstein's Gravito-Electromagnetism, Gravity of moving mass in General Relativity . In that, he discussed why maxwell's electromagnetism laws hold for special relativity also. He took the following situation:

Adam is in a spaceship or the reference frame of two charged particles such that their gravitational force cancels their electromagnetic repulsion. Adam would see no magnetic force since charges are at rest according to his frame. Now Sarah is watching Adam from a ground reference and sees the charges moving and hence they must exert an attractive magnetic force pushing particles towards each other. But now Eugene, said that a force (gravity) analogous to the magnetic force produced by moving charge, is produced by moving mass, which will be repulsive, and will balance the attractive magnetic force.

Now I became confused here, what is this "new gravity force"? I never heard about it before, at least in high school. Is it a mathematical trick or tweaking? Or is there really is a repulsive gravitational force that is exerted by moving masses? So this is my doubt here, can someone please explain this further?