-C, --advertise-credentials If the SFTP service is advertised via multicast DNS, this flag allows to put username/password inside the advertised TXT record
-S, --advertise-service Advertise SFTP service using multicast DNS (default true)
--allowed-extensions stringArray Allowed file extensions case insensitive. The format is /dir::ext1,ext2. For example: "/somedir::.jpg,.png"
--denied-extensions stringArray Denied file extensions case insensitive. The format is /dir::ext1,ext2. For example: "/somedir::.jpg,.png"
-d, --directory string Path to the directory to serve. This can be an absolute path or a path relative to the current directory (default ".")
-f, --fs-provider int 0 means local filesystem, 1 Amazon S3 compatible, 2 Google Cloud Storage
--gcs-automatic-credentials int 0 means explicit credentials using a JSON credentials file, 1 automatic (default 1)
In portable mode, SFTPGo can advertise the SFTP service and, optionally, the credentials via multicast DNS, so there is a standard way to discover the service and to automatically connect to it.
Here is an example of the advertised service including credentials as seen using `avahi-browse`:
```
= enp0s31f6 IPv4 SFTPGo portable 53705 SFTP File Transfer local