Update README.md

Author: jarrodwatts

README.md

@@ -72,11 +72,9 @@ Meanwhile, if you want to use write functions as well and connect a signer, you
 ```python
 from thirdweb import ThirdwebSDK
 from thirdweb.types.nft import NFTMetadataInput
-import os
 
-
-# This PRIVATE KEY is coming from your environment variables. Make sure to never put it in a tracked file or share it with anyone.
-PRIVATE_KEY = os.environ.get("PRIVATE_KEY")
+# Learn more about securely accessing your private key: https://portal.thirdweb.com/web3-sdk/set-up-the-sdk/securing-your-private-key
+PRIVATE_KEY = "<your-private-key-here>",
 
 # Now you can create a new instance of the SDK with your private key
 sdk = ThirdwebSDK.from_private_key(PRIVATE_KEY, "mumbai")