Once you've signed up you will see this page:
In order to authenticate your YouTube channel:
Click on the button “Authenticate with YouTube”.
Sign in to the Google account associated with your YouTube channel.
Allow access to your channel by clicking “Allow” button.
If you would like to add another channel to your vidIQ account:
Click the small triangle at the top right corner of vidIQ web platform.
Pulse the green button “Add Channel”.
Select another channel (if needed sign into the different Google account).
Allow access to you your channel by clicking “Allow” button.