of one's own free will
Lo hizo por voluntad propia.
He did it of his own free will.
Ella no se casó con él por voluntad propia.
She didn’t marry him of her own free will.
Me he entregado por voluntad propia.
I turned myself in of my own accord.
— Chicago (2002)
Y que vienes aquí por voluntad propia?
And you come here of your own free will?