Azure APIM oAuth workflow - refresh token is missing

I enabled oAuth in Azure API management. Then using ClientId, Client Secret, Scope, Access Token URL & Grant Type, I was able to get the access token. How can I get the refresh token from the API ?

To get refresh token from the API, you need to add offline_access permission in the scope.

Please note that, Client credentials flow works with permissions of Application type only. So, you won't get refresh token using this flow as offline_access permission is of Delegated type.

Instead, you can make use of Authorization Code flow as Grant Type.

I tried to reproduce the same in my environment via Postman and got below results:

In my Azure AD application, I added API permissions like below:

To get refresh token, change the grant type to Authorization Code and include offline_access in the scope like below:

When you selected Get New Access Token, one new window will open where you have to login with your credentials as below:

After successful authentication, you will get both access token and refresh token like below:

You don't have to make two separate calls like one to get access token and another one to get refresh token.

Instead, you can directly add offline_access in the scope along with custom Api scope.