roots = Reduce[ Sin[z^4] + z == 0 && -2 <= Re[z] <= 2 && -2 <= Im[z] <= 2, z];
roots[[1 ;; 3]]
Show[StreamPlot[{Re[Sin[(x + I y)^4] + (x + I y)], Im[Sin[(x + I y)^4] + (x + I y)]}, {x, -2, 2}, {y, -2, 2}], ListPlot[{Re[z], Im[z]} /. {ToRules[roots]}, PlotStyle -> Directive[PointSize[Medium], Red]]]