How to send a custom ringtone to a friend so that they can install it WITHOUT using a computer or itunes?

Hello!

I have made a number of custom ringtones that I would like to have available to friends for free. All of the solutions I am finding online for installing the ringtone on my friend's phone are insanely clunky, email them the file, then they have to run it through garageband just to get it installed.... or even worse connect it to a computer

Isn't there a simple way I can send someone a ringtone via email or imessage and they can just set it as their ringtone?

I am hoping to find a user friendly solution so that my grand father and his friends can do it easily without needing to navigate through the export options in garageband etc