Trouble adding wake_lock permission in AndroidManifest.xml.

Hi there
This is my first time asking on this forum, so please forgive me if I make a mistake (wrong etiquette, wrong forum etc)

My game keeps going to sleep on android.

I have added

Code (CSharp):

1.  
2.  Screen.sleepTimeout =SleepTimeout.NeverSleep;
3.  
4. ;

To the start of a singleton class which gets instantiated at the load of my splash screen.

As I understand it this should keep the screen on , but it does not work .

I understand that the wake_lock permission needs to be added to the AndroidManifest.xml file.

I cannot seem to find it in my project folder.

I even tried creating a folder .../assets/plugins/android/ and placing the partial android manifest there but this simply causes gradle to fail my build.

I removed the file before copying the error, but I can recreate the error if need be .

Any guidance here will be greatly appreciated.