Let \(P(x)\) be a real polynomial of degree 3 which vanishes at \(x=-3\). Let \(P(x)\) have local minima at \(x=1\), loc…

Let \(P(x)\) be a real polynomial of degree 3 which vanishes at \(x=-3\). Let \(P(x)\) have local minima at \(x=1\), local maxima at \(x=-1\) and \(\int_{-1}^1 P(x) d x=18\), then the sum of all the coefficients of the polynomial \(P(x)\) is equal to........

[JEE Main 2021, 18 Mar (Shift 2)]