In reference the following snowflake page:
At the top of the page it indicates:
External stage
References data files stored in a location outside of Snowflake. Currently, AWS S3 buckets or Microsoft Azure containers are supported.
Further down the document parameters are described for AWS and Azure and Google Cloud.
I don't know if this is the right place to report doc bugs, but I do know these forums are monitored by Snowflake staff.
Thanks,