Change web apps notification sound

Hi ambrozewicz,

Thanks for contacting Apple Support Communities!

We understand that you'd like to customize notifications for an app that you use within Safari, is that right?

If so, you can customize your Safari settings such as text size and display settings within Safari, but it doesn't offer a feature that would allow you to customize alert tones you receive from apps from within Safari. If you'd like to learn more about what features you can customize within Safari here's a handy resource for you: Customize your Safari settings on iPad - Apple Support

"Change other Safari settings

You can change other Safari settings in the Settings app.

From the Home Screen or App Library, go to Settings  > Safari, then adjust any of the options. For example:

• Search Engine: Choose the search engine to use when you enter search terms in the search field.
• Privacy & Security: Choose default security features across all websites.
• Downloads: Choose where to save your downloads from Safari.
• Safari Suggestions: Choose whether to allow Siri to suggest websites as you search.

You can also adjust Safari settings in Accessibility settings. Go to Settings > Accessibility > Per-App Settings. Tap Add App, choose Safari, then tap Safari to adjust the settings."

You could also contact the app developer directly to help you to determine if there are any settings within the app you can adjust for your notifications.

We hope this helps.

Cheers!