hmacSha256 issue in custom template in server-side GTM and CloudRun setup

[YuliyanY]

Hi,

I am facing an issue where invoking hmacSha256() method in a custom template in server-side GTM throws an error "The JSON file referenced by the SGTM_CREDENTIALS environment variable does not exist or is incorrectly formatted." even though SGTM_CREDENTIALS exist and is linked to a secret. I can access the secret and view it. The service account also has permissions to access secrets and the secret is formatted as a JSON object with key:value pairs and obviously I am referencing the secret key when invoking the hmacSha256() method. 

Strangely, the documentation on how to create the SGTM_CREDENTIALS was not what I experienced in CloudRun, when creating this variable it was straight forward and I was never asked for any path to secret, it was jsut a dropdown to select which one should be referenced, so I am thinking is the documentation and the hmacSha256()/SGTM_CREDENTIALS  for AppEngine setup? Anyone aware of this issue for CloudRun sGTM setup or how to make this work with CloudRun sGTM setup?

Thanks