St. Paul says, indeed, that whoever knew no sin, (God) made him sin for us, so that we would become God's righteousness in him. That is to say that Jesus, like us in everything except sin (cf Heb 4, 15), his Father and our Father made him a propitiatory victim so that justice would be satisfied for the sins of men: The phrase "made him Sin for us means "that He gave to Him - totally innocent - the treatment we deserved. He carried on his Son the responsibility of our sins, without these sins having any intrinsic relationship with Him. Sin as such.
Thanks for sharing @ giacamila777.