move rigidbody without velocity code example

Example 1: rigidbody freeze position through code

rigidbody.constraints = RigidbodyConstraints.FreezeRotationX | RigidbodyConstraints.FreezeRotationZ;

Example 2: unity move with rigidbody.moveposition

rb2D.MovePosition(rb2D.position + velocity * Time.fixedDeltaTime);