Calling .net Core API secured with OKTA oauth

Hi Folks,
If i need to secure my Web API using oauth. where should i configure under OKTA dashboard. Is Application->create new application->Service?

I have configured under Service and created the client_id and client_secret. From my core, i received the token by passing the client_id and client_secret with grant_type as ‘client_credentials’ and i received 200 response with toke. When i add this token to my call to Web API, im getting unauthorized error. I can see ‘OAuth2 access token is granted’ in the Okta dashboard. is something im missing here?
Appreciate your help on this