For ANDRIOD Phones :
1. Click and download the audio from the link below. It will get saved on your phone.
2. Go to settings Sounds and Vibrations Call Ringtones
3. Select the audio you downloaded

For Iphone :

Follow this video to use a downloaded audio as Ringtone on your iPhone :
https://youtu.be/dcVkINlatGo?si=Dr-S4EHZocrZEVxz