Vector Algebra: JEE Main 2020 Mathematics question

Let the position vectors of points 'A' and 'B' be $\widehat i + \widehat j + \widehat k$ and $2\widehat i + \widehat j + 3\widehat k$, respectively. A point 'P' divides the line segment AB internally in the ratio $\lambda$ : 1 ( $\lambda$ > 0). If O is the origin and $\overrightarrow {OB} .\overrightarrow {OP} - 3{\left| {\overrightarrow {OA} \times \overrightarrow {OP} } \right|^2} = 6$, then $\lambda$ is equal to______.