auth_failed Key may not be empty response

Greetings,

I’m not a WP expert, so please bear with me. I’m trying to use this plugin to handle static and media files, since WP is deployed in Docker Container on Cloud Run, for DB I’m using Cloud SQL.
I copied all files into wp-content/plugins/wp-stateless and deployed.
I’ve activated the plugin via WP-Admin, set manually service account, set bucket, permissions, but when I try to Sync, I get a message: “Errors encountered. Try reloading the page. Key may not be empty”

When looking at Chrome Dev tools I see that it makes request to:
“/index.php?rest_route=/wp-stateless/v1/sync/getProcesses” and gets response:
{“code”:”auth_failed”,”message”:”Key may not be empty”,”data”:{“status”:401}}

I tried to do also Automatic setup, but that doesn’t help either.

I’m not sure if this issue is directly related to WP-stateless or perhaps something else. Tried to search on Google, but couldn’t find anything based on that message.

Any help or guidance will be much appreciated.