Apple have improved security to iTunes Connect, and now require you to generate a separate Access Token when you share your details with external parties. This ensures that the password we use to gather your sales is separate from the one you use to log into iTunes Connect.
Log into your account at: https://itunesconnect.apple.com.
Click on “Sales and Trends”.
Click on “Reports” on the dropdown menu.
Click on the tooltip next to About Reports.
Click on “Generate Access Token”.
Copy the Access Token.
Paste the Access Token in the Link Account form on Reflection