How to change the default environment variables ?

[premdasvm]

How can i change the default value of ${{ github.actor }} from nektos/act to something else?

[shubhbapna]

You should be able to change it by overriding the corresponding env variable like this --env GITHUB_ACTOR=actor. Although maybe for github.actor this was missed and it might not work:
https://github.com/nektos/act/blob/master/pkg/runner/run_context.go#L624

[premdasvm]

It doesn't work.