For Android:
Open your device's "Settings."
Navigate to "Sound" or "Sound & Vibration."
Tap on "Ringtone" or "Phone ringtone."
Choose the downloaded tonos para whatsapp from the list of available options.
For iPhone:
Open the "Settings" app.
Scroll down and tap on "Sounds & Haptics."
Under "Sounds and Vibration Patterns," tap on "Ringtone."
Select the downloaded ringtone from the list.
For Windows Phone: