90.txt

Secure your API using subscriptions
CourseAPIManagement service -> APIs -> Courseproject.API, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null ->
/Address/Get Get -> Type (Request url)https://courseprojectapimanagement.azure-api.net/Address/Get in browser ->
{ "statusCode": 401, "message": "Access denied due to missing subscription key. Make sure to include subscription key when making requests to an API." }

Why?
Under Settings Tab -> Subscription required checkbox checked

CourseAPIManagement service -> Subscriptions -> Add subscription

CourseAPIManagement service -> APIs -> Courseproject.API, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null ->
/Address/Get Get -> Type (Request url)https://courseprojectapimanagement.azure-api.net/Address/Get?subscription-key=bdce9d97f7b34c0db7bfdd819b32b4ed
 in browser -> [{"id":"1","street":"string","zip":"string","city":"string","email":"test@test.com","phone":"string"}]

Postman.com -> My workspace -> New HTTP request -> Enter url (https://courseprojectapimanagement.azure-api.net/Address/Get)
-> Header value from(Under Settings Tab -> Subscriptions section) -> (Ocp-Apim-Subscription-Key) copy paste this 
Header under Key and the bdce9d97f7b34c0db7bfdd819b32b4ed(key value) in Value -> Send

Usecase:
This method suits you if you don't have identity users that are really end users using your API.
But if you more have like other services using your API , 5 other companies using your API(5 subscriptions for each)
But 1000 of users, you want to use another technique to secure your API.