You can find it by going to API Management services, then APIs. Select your API, your endpoint and then select the Test tab on the right hand side. Go down to Headers and against Ocp-Apim-Subscription-Key you will see it hidden; select the eye to see it.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…