Catalyzes the multi-step reaction: L-Tryptophan + 2 Oxygen + 2 NADPH + 2 H+ = Indole-3-acetaldehyde oxime + 3 H2O + 2 NADP+ + CO2. The individual reactions are: (1a) L-tryptophan + O2 + NADPH + H+ = N-hydroxy-L-tryptophan + NADP+ + H2O,(1b) N-hydroxy-L-tryptophan + O2 + NADPH + H+ = N,N-dihydroxy-L-tryptophan + NADP+ + H2O, and (1c) N,N-dihydroxy-L-tryptophan = (E)-indol-3-ylacetaldoxime + CO2 + H2O.