Update README.md

Author: cryptochassis

README.md

@@ -780,7 +780,7 @@ Subscription subscription("okx", "BTC-USDT", "ORDER_UPDATE", "", "", {
 ```
 
 #### Override exchange urls
-You can override exchange urls at compile time by using macros. See section "exchange REST urls", "exchange WS urls", and "exchange FIX urls" in [`include/ccapi_cpp/ccapi_macro.h`](include/ccapi_cpp/ccapi_macro.h). You can also override exchange urls at runtime. See [this example](example/src/override_exchange_url_at_runtime/main.cpp). These can be useful if you need to connect to test accounts (e.g. https://www.okx.com/docs-v5/en/#overview-demo-trading-services).
+You can override exchange urls at compile time by using macros. See section "exchange REST urls", "exchange WS urls", and "exchange FIX urls" in [`include/ccapi_cpp/ccapi_macro.h`](include/ccapi_cpp/ccapi_macro.h). You can also override exchange urls at runtime. See [this example](example/src/override_exchange_url_at_runtime/main.cpp). These can be useful if you need to connect to test accounts (e.g. https://www.okx.com/docs-v5/en/#overview-demo-trading-services) or connect to an IP address (e.g. ws://172.30.0.146:9000).
 
 #### Complex request parameters
 Please follow the exchange's API documentations: e.g. https://www.okx.com/docs-v5/en/#order-book-trading-trade-post-place-order.