chore: update main.go

main.go

@@ -71,7 +71,7 @@ func request(client *http.Client, method, url string, body interface{}) (*http.R
 		return nil, fmt.Errorf("failed to create request: %w", err)
 	}
 
-	req.Header.Set("X-API-Key", portainerToken)
+	req.Header.Set("X-API-KEY", portainerToken)
 	req.Header.Set("Content-Type", "application/json")
 	return client.Do(req)
 }