The safari in my iPhone 6 can not play audio file in Wikipedia, for example, the following picture shows a audio file one a Wikipedia page but I cannot play it. what's wrong with it and how to fix it?
Actually, Wikipedia provided solutions for this, Wikipedia:Media help (audio and video)
It is highly recommended that you use a program which is capable of playing both Vorbis audio and Theora video since these two different media formats are often in the same digital container format, Ogg.
In Wikipedia create an account and login. Then you can play ogg files. For example this: https://en.m.wikipedia.org/wiki/File:Cher_-_Dark_Lady.ogg
For other sites I don't have any specific solutions. But obviously Safari supports ogg, at least in iOS 14.2