2-3 weeks, you want the pistils to be red/brown and shriveled back into the caylx. The trichs should be cloudy. The amount of amber trichs you want is a personal preference.
If your Kush autos popped on May 5, they’re about 9 weeks in now. Most autoflowers take around 10–12 weeks from seed to harvest, so you’re getting close! Check the trichomes, cloudy with some amber means they’re ready. You’ve likely got 1–3 weeks left.