jobs.<job_id>.steps[*].env to set environment variables for steps to use in the runner environment.
You can also set variables for the entire workflow or a job.
When environment variables have matching names, the CloudBees platform uses the most specific variable.
env defined in a step overrides job and workflow environment variables with the same name, while the step executes.
env set in a job definition overrides a workflow variable with a matching name, while the job executes.
Public actions may specify expected variables in the README file.