I\'ve looked everywhere and it seems people either use pubsub, app engine http or http with no auth. Not too many people out there showing their work for accessing functions
1.I created a clod function (in the same region as my App Engine Application), which does not allow public access
2.I created a service account with Owner role
3.I created the cloud scheduler job:
url = https://europe-west2-my-project.cloudfunctions.net/my-function
oidc-token
newly created service account
audience = https://europe-west2-my-project.cloudfunctions.net/my-function
Everything worked as expected. Please double check your set up because it should work.