Hi,
I've defined my OAuthV2 policy as below
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<OAuthV2 async="false" continueOnError="false" enabled="true" name="GenerateAccessTokenClientV2">
<!-- This policy generates an OAuth 2.0 access token using the client_credentials grant type -->
<Operation>GenerateAccessToken</Operation>
<!-- This is in millseconds, so expire in an hour -->
<ExpiresIn>30000</ExpiresIn>
<ExternalAuthorization>false</ExternalAuthorization>
<StoreToken>false</StoreToken>
<SupportedGrantTypes>
<GrantType>client_credentials</GrantType>
</SupportedGrantTypes>
<GrantType>request.formparam.grant_type</GrantType>
<GenerateResponse enabled="true"/>
</OAuthV2>
But I still get an error
{"fault":{"faultstring":"Unresolved variable : external_access_token","detail":{"errorcode":"entities.UnresolvedVariable"}}}
Not sure why it is looking for external_access_token when I clearly mentioned grant_type client_credentials
This could be related to your StoreToken attribute being set to false. It should be set false when using External Authorization.