Add a new Zendesk Support widget from your dashboard.
Select a preset widget from the list, or choose to Build your own widget.
Enter the subdomain of your Zendesk account. The subdomain can be found from your login details. For example, if you log in to Zendesk at https://mycompany.freshdesk.com, your subdomain is mycompany.
Click Connect via Zendesk on the connection panel. You'll now be asked to log into your Zendesk account, unless you're already logged in. You'll be asked to give Geckoboard permission to access your account.
Geckoboard will now fetch data from the last 31 days. You can continue to edit your dashboard and widgets while it continues in the background. You'll only need to do it once (per new per new Zendesk connection) and it'll help speed up your experience.
To connect a different Zendesk Support account to the one you've already connected to Geckoboard, see connect multiple accounts to data sources.