How to Export Your Blockchain.com Extended Public Key (xPub)
From your http://Blockchain.com, account click the Settings item in the left menu and select Addresses.
The Addresses screen will list your available wallets. Each wallet will have a Manage link along the right side of the screen. Click the Manage link and you will see a More Options link.
Click More Options and then select Show xPub. A warning dialog will appear explaining that you should only give an xPub to those you trust. Click continue.
You will then be able to copy your xpub yet and paste it into NODE40 Balance to begin uploading your transactions from Blockchain.com Wallet.