Creating console variables in C++; syntax?

I have tried following the UE4 Console Command documentation but it seems to be outdated (like so often…).

I have tried adding a console variable as described in the documentation; I added the following line in the header file of an actor (the docs say it can be created in any C++ file):

static TAutoConsoleVariable <_ float_> CVarProjectileSpeed(TEXT(“g.ProjectileSpeed”), 3000.f, TEXT(“Geschwindigkeit des Projektils”), ECVF_Cheat | ECVF_SetByConsole);

However, when I try to compile this, I get the following error message multiple times:

c:\users\mateo egey\documents\unreal projects\fpsprojectcpp\source\fpsprojectcpp\FPSProjectile.h(36): error C2059: syntax error: ‘string’

When I click the error it links me to that exact line. I don’t know why it complains about a string being used. I’m including the IConsoleManager.h as well.
What is the error reponsible for that behavior? Where have I done something wrong?

Kind regards