Spring Boot: Full authentication is required to access this resource

Question

I am doing example of Spring Boot Security with wso2is server from this post https://github.com/angel-git/wso2is-springoauth, when I am trying to access resource with access token I am getting

{"error":"unauthorized","error_description":"Full authentication is required to access this resource"}

I am generating access token by:

curl -u CLIENT_ID:CLIENT_SECRET-k -d "grant_type=password&username=admin&password=admin" -H "Content-Type:application/x-www-form-urlencoded" https://localhost:9443/oauth2/token

and accessing resources by:

curl -H GET "Authorization: ACCESS_TOKEN" http://localhost:8080/greeting

I found many solution on stackoverflow but unfortunately could not solve my issue

please help, thank you