Nah, on iPhones you need to make the ringtone file using garage band, which I’m pretty sure you can only really do on a Mac or by paying for some license for transferring on windows/linux maybe? Or you need to pay for it through iTunes or another paid app. I genuinely haven’t found a way to do it without paying yet (don’t have a Mac and transfers to and from windows/linux are awful), and I’ve looked long and hard as my custom notifications were important to me..

If someone can tell me otherwise, I’m all ears tho.