Coordinate Geometry: JEE Main 2020 Mathematics question

Let the line y = mx and the ellipse 2x² + y² = 1 intersect at a ponit P in the first quadrant. If the normal to this ellipse at P meets the co-ordinate axes at $\left( { - {1 \over {3\sqrt 2 }},0} \right)$ and (0, $\beta$), then $\beta$ is equal to :