Open Apollo and select People from the left navigation menu.

Run any search with your desired filters
Locate the Emails column header
Click on the Emails dropdown menu
Select Edit field from the options

This opens your organization's waterfall enrichment configuration panel.
In the Enrichment configuration section, you'll see your current data sources listed
Make sure Enable Waterfall for your team is toggled on
Locate LeadMagic in your data sources list
Click the settings icon (gear symbol) next to LeadMagic

When the API key dialog appears, enter a descriptive name in the Key name field (e.g., "LeadMagic-Apollo")
Paste your LeadMagic API key in the API key field
Click Save

Click Save & run at the bottom of the enrichment configuration panel
Confirm that you want to apply these changes across your entire team's Apollo account