I can not find an option (a clean one) that allows to set the Server URL or Api Url and they seem to be hardcoded to github.com.

Prepare publishing assets
  [INFO] ForceOrphan: false
  /usr/bin/git clone --depth=1 --single-branch --branch gh-pages ***github.com/coresystemsFSM/blog.git /home/runners/actions_github_pages_1615224725805
  Cloning into '/home/runners/actions_github_pages_1615224725805'...
  remote: Invalid username or password.
  fatal: Authentication failed for 'https://github.com/coresystemsFSM/blog.git/'

This fails because our repo is at https://github.tools.sap/coresystemsFSM/blog

As we want to use your action with GitHub Enterprise we would need to be able to customise those.

Link to your contents

I see one entry here but I think its unused during a workflow.

Additional context

I would contribute a PR if you give me 1-2 pointers where I'd need to add things in your structure.