You can look at help message to get available options:
$ go run cmd/consul-backup-s3/main.go --help
Usage of /tmp/go-build3397545109/b001/exe/main:
--backup.schedule string crontab format schedule for backup create (default "0 0 * * *")
--backup.ttl string golang duration format ttl (default "744h0m0s")
--consul.address string consul server http address (default "http://127.0.0.1:8500")
--consul.ca-file string consul server CA file
--consul.ca-path string consul server CA path
--consul.client-cert string consul client cert file
--consul.client-key string consul client key file
--consul.datacenter string consul datacenter name
--consul.tls-server-name string consul server name for tls communication
--consul.token string consul server token
--consul.token-file string consul server token file
--s3.bucket string s3 bucket name for upload (required)
--s3.endpoint string s3 endpoint url
--s3.prefix string s3 backup store location prefix
--s3.region string s3 bucket region
pflag: help requested
exit status 2
For not amazon cloud provider, you need specify endpoint and region.
Schedule option support cron like notation. Also supported values like "@hourly", "@daily", "@weekly", "@monthly", "@yearly", "@annually" and "@every duraton"(duration must be parsable with time.ParseDuration).