transformationService of type 'REGEXP' is unavailable

I’m getting an error with REGEXP is unavailable in this items file, I have installed the transformation addon
eg. Extension ‘transformation-regex’ has been installed.

items
Number Daikin_Get_Control_String "Daikin set temperature [%s]"  { http="<[http://192.168.0.6/skyfi/aircon/get_control_info?lpw=:60000:REGEXP(stemp=(.*),)]" }
log
2019-06-24 18:49:27.025 [WARN ] [.core.transform.TransformationHelper] - Cannot get service reference for transformation service of type REGEXP
2019-06-24 18:49:27.026 [WARN ] [ab.binding.http.internal.HttpBinding] - Couldn't transform response because transformationService of type 'REGEXP' is unavailable

doh … spelt REGEX wrong…