How to get GitHub secrets of host repository as input in github action?

We have a repository named recent-activity which hosts (contains source code of) a workflow that can be used by anyone on GitHub. We want to add some secret keys to the source code of this workflow. Those secret keys should be accessible to the workflow whenever any user runs the workflow on their respective repository. Since the workflow is open source, we are unable to add the keys directly to the workflow code.
So we tried to use GitHub secrets. We added a secret to the repository that contains source code of the workflow. How can this secret be accessed when anyone uses this workflow on their own repository?
Also, if this is an incorrect way to go, what would be the correct one?