Here is more information on the fields required to set up your Google Cloud Storage with Rocket.Chat using a service account.
Set the following fields:
Google Storage Bucket Name
The bucket name you created on Google Storage
Google Storage Access Id
The access ID (or username) of the service account that has access to your Cloud Storage bucket, usually in the following format: email@example.com
Google Storage Secret
Essentially a PEM that contains your private key and certificate
Google Storage Secret: the value pushed here takes an argument of a PEM file to connect to your Cloud Storage bucket. When you create a service account, you have the ability to download a JSON file that contains a number of variables. You need the unescaped private key, along with one of the certificates linked at the bottom of the JSON.
Syntax then looks just like a regular PEM file:
-----BEGIN PRIVATE KEY-----unescaped private key goes here-----END PRIVATE KEY---------BEGIN CERTIFICATE-----first certificate goes here-----END CERTIFICATE-----
Enter this into Rocket.Chat to allow the authentication with Google and store items in the bucket.