Hi @aimuz tnx for asking! This Github Action leverages the V2 API endpoint “trigger pipeline” CircleCI API
This V2 API endpoint is not compatible with the new Github App or Gitlab project types, and currently works for the old Github Oauth and Bitbucket type projects.
NB If your project slug starts with “circleci/” you have a new Github App or Gitlab project type.
The new “generic inbound webhook triggers” DO work with Github Apps, and might be an option to leverage (with or without Github Actions) to trigger a pipeline. Afaik they have a limitation in that they don’t support parameter or branch/tag settings, they only work on the default branch. More info can be found here: Trigger pipelines from anywhere: inbound webhooks now in preview - #4 by rit1010