Hello, i'm sharing the php code to send push notifications trough your apps with OneSignal.
Copy the php code and upload it to a server with curl support.
COPY PHP CODE FROM HERE
Download aia project.
Import the project and just change the Url, AppId
Change this to Textbox2.Text
you will see a workaround that i made in the Web1.GotText to detect if push notification succeed or fails.