Let \( O \) be the vertex of the parabola \( x^2 = 4y \) and \( Q \) be any point on it. Let the locus of the point \( P \), which divides the line segment \( OQ \) internally in the ratio \( 2:3 \) be the conic \( C \). Then the equation of the chord of \( C \), which is bisected at the point \( (1, 2) \) is:
