Update README.md

1 files changed, 1 insertions, 1 deletions

diff --git a/README.md b/README.md
index ddff138..5f7dd34 100644
--- a/README.md
+++ b/README.md
@@ -69,7 +69,7 @@ namespace Example
     {
         private static void Main()
         {
-	    String apiKey = Environment.GetEnvironmentVariable("SENDGRID_APIKEY", EnvironmentVariableTarget.User);
+            String apiKey = Environment.GetEnvironmentVariable("NAME_OF_THE_ENVIRONMENT_VARIABLE_FOR_YOUR_SENDGRID_KEY", EnvironmentVariableTarget.User);
             dynamic sg = new SendGridAPIClient(apiKey);
 
             Email from = new Email("test@example.com");