Log in to Deel, go to the "App Store" in the left sidebar, then go to "Developer Center":
Go to the "Apps" tab, then click on "Create New App":
Next, select "Organization" as the app type. Enter a name under "App name". Enter "https://connect.kombo.dev/v1/oauth/deel/callback" as the "Redirect URL". Enter the rest of the required information.
Copy the "Key" and "Secret", as you'll need this in the next step:
Finally, under "Tools > Deel" in the Kombo Dashboard, enter your "Key" and "Secret" under "Client ID" and "Client Secret" respectively, and hit "Save":