I'm getting "ERROR SyntaxError: Unexpected end of JSON input"

[bitfede]

Hello, I followed the instructions on how to install the buildpack, but I get this error in the heroku console when I try to invoke google cloud storage functions:

2022-12-13T20:32:28.601333+00:00 app[web.1]: ERROR SyntaxError: Unexpected end of JSON input
2022-12-13T20:32:28.601354+00:00 app[web.1]:     at JSON.parse (<anonymous>)
2022-12-13T20:32:28.601354+00:00 app[web.1]:     at ReadStream.<anonymous> (/app/node_modules/google-auth-library/build/src/auth/googleauth.js:346:39)
2022-12-13T20:32:28.601355+00:00 app[web.1]:     at ReadStream.emit (node:events:513:28)
2022-12-13T20:32:28.601368+00:00 app[web.1]:     at endReadableNT (node:internal/streams/readable:1359:12)
2022-12-13T20:32:28.601369+00:00 app[web.1]:     at process.processTicksAndRejections (node:internal/process/task_queues:82:21)

I ran $ heroku run cat google-credentials.json and the output was empty:

What should I do to debug this problem? Thank you so much!