From the Manage Properties tab, click on Social Media Accounts in the top right corner. Next, click the blue Add Social Account button and select YouTube.
A modal will pop-up and allow you to choose to add your account or a brand account to SND. Once you've selected the account, you'll be promoted with messaging to allow SND to view YouTube Analytics reports for your YouTube content, in addition to managing your YouTube account. Click allow and then click Add Channel to add your YouTube Channel.
Once your YouTube account has been added to the Dashboard, be sure to assign users to the account.