You refer to Amazon Echo Control - Bindings | openHAB
but I think what you would like to do is to run the “Good Morning” routine. Just send “Good Morning” to the item that is linked to the startRoutine channel. This then will be have like you would have said “Alexa, Good Morning”.
On your phone / in the app you define the / a routine.
In this case it is called “Good Morning” resp. you define any other phrase.
Then in the app you define the action that alexa will execute. In this case it is “Random Answer”.
Write a rule (in OH) triggered by the “lastVoiceCommand” channel and send your answer via “textToSpeech” command of the Echo Control Binding from this rule.
Be aware so the “lastVoiceCommand” tends to break due to changes on amazon side and you might need an updated Echo Control Binding from GitHub - smarthomej/addons: SmartHome/J addons for openHAB which is ususally updated before the official AddOn.