How to use a ringtone I got off the computer on an iPhone 6?

I have an iPhone 6 and I downloaded a ringtone I want to use on my phone. Its in the proper format and does not go over the limit of 30 seconds.

I've tried emailing the ringtones file and opening my mail on my iPhone to try and download it but it just plays. I've tried texting the ringtone to my phone but I can't get it to save onto my phone. Even when I press my finger onto the screen the only options that come up are Copy, Save and More. I tried Save but it doesn't tell me where its saving it to and all More brings up is a plan screen with lines and "Activity" at the top and I can't do anything.

Pressing "Save" should do it. It doesn't really matter where it's saved, once it is downloaded it should give you the option to use it. If that doesn't work, try downloading the ringtone on the phone itself instead of the computer.