Under Organizer settings → Integrations you store credentials (API keys) of external services at organizer level, grouped by service type.
Add an integration
Choose the service type and click New integration
Enter the name and the API Key (required) and an optional description
Click Add integration
The key is stored hidden: the dashboard never shows it in full again. From the list you can edit each integration's name and description, or delete it.
Don't confuse this with the event integrations (such as Copernico by Timingsense), which are configured event by event from the event menu.