Return strings to Blueprint

Hi, I’m try to get data form HTTP server and return it to Blueprint.
Like this:

Using this tutorial:…est_in_C%2B%2B

I have two problems.
Function from this tutorial is not static, so returning variables don’t work like this:

void AMCPApiClient::mcpStationIdentify(FString XApiKey, FString& IDstacji, FString& Nazwa)

When I change it to static I have an errors: