Everybody's already on iOS 12 or later, right? One of the most exciting features Apple introduced with their September 2018 update is Siri Shortcuts. Specifically for Lightbow, you can now activate any preset with a completely custom phrase of your choice. The app doesn't need to be open first—just ask Siri.
First, you need to pick a preset. You can either create one on your own using Lightbow's incredible preset editor, or add one of the hundreds of animated light & sound presets under the Browse tab. If you need help creating your own, check out tutorials on Mastering the Preset Editor. For now, let's choose the "Finale" preset from the FIREWORKS collection. (Tap the + to add it to your main Presets list)
Next, go to the Triggers tab, and tap the row that says "Siri Shortcuts". This will then show you all the existing shortcuts you've already set up with Lightbow (and this is the place you can delete them later if you change your mind). For now, tap "Add Preset", choose the preset you like, and Siri will walk you through recording a custom phrase. You can make it anything you want, as long as it doesn't conflict with something else Siri is listing for. Obviously you can't make a preset run on "Set a timer for 30 minutes" because that's reserved for something else.
That's it! Whenever you say your activation phrase in the future, Siri will launch Lightbow and activate the preset you chose.