API key required for ipdata.co.

README_API_GUIDE.md

@@ -454,8 +454,8 @@ IP Address Lookups
 
 ### Ipdata.co (`:ipdata_co`)
 
-* **API key**: optional, see: https://ipdata.co/pricing.html
-* **Quota**: 1500/day (up to 600k with paid API keys)
+* **API key**: required, see: https://ipdata.co/pricing.html
+* **Quota**: 1500/day for free, up to 600k with paid API keys
 * **Region**: world
 * **SSL support**: yes
 * **Languages**: English

lib/geocoder/lookups/ipdata_co.rb

@@ -12,6 +12,10 @@ module Geocoder::Lookup
       [:https]
     end
 
+    def required_api_key_parts
+      ["api_key"]
+    end
+
     def query_url(query)
       # Ipdata.co requires that the API key be sent as a query parameter.
       # It no longer supports API keys sent as headers.