File upload trough Google Cloud Storage not working (Invalid JWT Signature)

Description

I want to switch the uploads from GridFS to Google Cloud Storage. I created a service account in Google Cloud and created a new project for these file uploads.
In RocketChat, under “File Upload” > “Google Cloud Storage” I filled in all details of my newly created bucket.
The only field im not sure of is Google Storage Secret. It uses the format from the website docs: https://rocket.chat/docs/administrator-guides/file-upload/google-cloud-storage/
But it does seem conflicting with the instructions below the field in the admin section of RC:
" Please follow these instructions and paste the result here."
Because when following that link im not sure what result I should get somewhere or should copy paste? I did follow the private key step and the CORS step. I didnt follow the the /privte directory step and the “Declare Google Cloud Storage Directives” step. As they dont really make sense to me and are not clear if this applies for RocketChat.

Server Setup Information

  • Version of Rocket.Chat Server: 1.3.2
  • Operating System: CentOS
  • Deployment Method: tar
  • Number of Running Instances: 1
  • DB Replicaset Oplog: Enabled
  • NodeJS Version: v8.11.2
  • MongoDB Version: v3.4.22
  • Proxy: nginx

View Logs output:

I20190827-09:34:31.421(0) Setting default file store to GoogleCloudStorage
I20190827-09:36:28.146(0) Exception while invoking method ‘ufsComplete’ Error: invalid_grant: Invalid JWT Signature. at /opt/Rocket.Chat/programs/server/npm/node_modules/gtoken/build/src/index.js:272:35 at /opt/Rocket.Chat/programs/server/npm/node_modules/meteor/promise/node_modules/meteor-promise/fiber_pool.js:43:40