Based on the needs that you want to ahcieve, you could not use the combination of "PowerApps" button trigger and "When an item is created" trigger together within your flow (Microsoft Flow is enough for your needs).
If you fire your flow when click "Submit" button in your app, the "PowerApps" trigger button in your flow would be fired, but the "When an item is created" trigger would not. The "When an item is created" trigger would only be fired when another new item is added into your SP list.
In other words, the "PowerApps" button trigger and "When an item is created" trigger would not be fired at the same time in your flow.
Please consider achieve your needs using Microsoft Flow directly rather than fire a flow from your app.
Community Support Team _ Kris Dai If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.