IPhone 5s ITunes Radio not supported
Do you fulfil these requirements?

Apple Music Radio requirements  

To listen to Apple Music Radio, you need:


iOS 8.4 or later on your iPhone, iPad, or iPod touch. Update your iPhone, iPad, or iPod touch.
iTunes 12.2 or later on your Mac or PC. Get the latest version.
An Apple ID.


Apple Music Radio is available only in select countries. Find out what's available in your country.  

Apple Music Radio features vary by country.  

In some countries, an Apple Music membership is required to listen to Apple Music Radio.

Source: https://support.apple.com/en-gb/HT204944