oauth

I've been trying to integrate the Coinbase API in my app for some time now. I was able to login and get access key with OAuth using webview. I am only having problems Sending money doc: curl https://api.coinbase.com/v2/accounts/2bbf394c-193b-5b2a-9155-3b4732659ede/transactions / -X POST \...

I need to implement an OAuth2 Authorization Server in B4J but I only seem to find threads on client implementations (e.g. B4J which authenticate to public OAuth services like Google or Facebook). Is there anyone who has done or tried this already and want to share some ideas, starting points...