pyttsx3 is not changing voices an i think its because i use google colab

Question

i Use google colab and pyttsx3 is not changing voices i also want to know how to add custom voices if possible

sound_engine = pyttsx3.init()
voices = sound_engine.getProperty("voices")
sound_engine.set_property("voice", voices[1].id)
sound_engine.setProperty("rate", 150)