How to use UART4 on a STM32L475IOT board? I want to connect a GPS module with NMEA output

[Kde G.2]

I use the STM32 System Workbench, tried examples of other boards. The system does not see my main.h and says: Symbol UART4 cannot be resolved. Compilation gives no errors, but in the source I see those undefines being red underlined.