As per Logstash reference docs 8.15 and http input * Plugin version: v3.8.1 only http basic authentication is supported.
Please add support for OAuth2 Bearer tokens, otherwise http input plugin is little/no use with any OAuth protected http resources, which are in high majority in 2024.
It would be beneficial to leverage Logstash Secrets Keystore to store credentials in a secure way and perform OAuth2 without leaving pipeline code.
There is one post that mentions Ruby workaround How to generate OAUTH2 token and use REST API to pull logs from Cloud? but please update the docs and share official documentation as OAuth2 is standard authentication for http.
Thanks