The "push" command:

Usage: fossil push ?URL? ?options?

Push changes in the local repository over into a remote repository.
Use the "-R REPO" or "--repository REPO" command-line options
to specify an alternative repository file.

If the URL is not specified, then the URL from the most recent
clone, push, pull, remote-url, or sync command is used.

The URL specified normally becomes the new "remote-url" used for
subsequent push, pull, and sync operations.  However, the "--once"
command-line option makes the URL a one-time-use URL that is not
saved.

Use the --private option to push private branches to the
remote repository.

See also: clone, pull, sync, remote-url