Notification about audio download vs. streaming

For some contexts where the users pay their mobile data according to their usage, it would be good to alert them to the two different options. Yes we can write about it in the About Text or the App Description but it would be better if a notification appears that alerts them to the two different options and let’s them select it. It doesn’t need to appear every time but might be great if it shows at the first time the audio is used.