Adding an API key to Sansheets is very simple. But there is two things you need to do first:

and

In case those are already done you can continue adding that API key to Sansheets.

You will find the option to add an API key in the Add-ons menu under Santiment Data:

A popup will open asking you for your API key:

Copy it from the Sanbase account settings and paste it here, then click Ok.

Sansheets will now confirm that you entered a valid API key:

You will now have access to more data, depending on your stake of SAN tokens.