Build the HTTP Authorization: Basic header value for client_secret_basic. Per RFC 6749 §2.3.1, both the client identifier and password are percent-encoded (application/x-www-form-urlencoded) before concatenation.
Build the HTTP Authorization: Basic header value for client_secret_basic. Per RFC 6749 §2.3.1, both the client identifier and password are percent-encoded (application/x-www-form-urlencoded) before concatenation.