Hi @legobricks ,
Curious on the error that you are getting. However, for GCS - https://cloud.google.com/storage/docs/buckets#naming I do see underscores are allowed but there is also a note below:
You can use a bucket name in a DNS record as part of a CNAME or A redirect.This means that your bucket name should not use underscores (_) or have a period next to another period or dash. For example, .., -., and .- are invalid character combinations within DNS names.
This lists the general bucket naming rules for AWS. https://docs.aws.amazon.com/AmazonS3/latest/userguide/bucketnamingrules.html
Thanks!