Alexa can't find TargetTemperature tagged Item

I have alexa connected and can turn switches on & off. But Alexa can’t find the targetTemperature tagged device… It’s listed in myopenhab as

{"link":"https://home.myopenhab.org:443/rest/items/MainHall_Target_Temp","state":"19","type":"Number","name":"MainHall_Target_Temp","label":"Hall Target","category":"temperature","tags":["TargetTemperature"],"groupNames":[]}

Any ideas?