Add a new Matomo Cloud widget from your dashboard.
Select from the list of preset metrics, or build your widget from scratch.
In the connection panel, enter your Account name. This forms part of your Matomo url, {account}.matomo.cloud.
Select which Domain your Matomo account is located. This should match the domain you use to log in to Matomo.
Enter your Matomo API key. This can be generated by going to Personal > Security.
Once authenticated, you'll be taken to the widget configuration screen. Learn about the configuration options for Matomo widgets.
To connect a different Matomo account to the one you've already connected to Geckoboard, see connect multiple accounts to data sources.