client_id or redirect_uri can't be verified against aPOST /api/oauth/authorize below), which redirects the browser backredirect_uri with either ?code=…&state=… (RFC 6749 §4.1.2) or?error=…&error_description=…&state=… (§4.1.2.1).code_challenge + code_challenge_method=S256) is mandatory:plain is rejected outright, and a request missing PKCE fieldscurl --location 'https://upload.tf/api/v1/oauth/authorize?client_id=undefined&redirect_uri=undefined&response_type=undefined&scope=undefined&code_challenge=undefined&code_challenge_method=undefined&state=undefined&resource=undefined' \
--header 'x-api-key: <api-key>'{}