Function update 

pub async fn update(
    conn: ConnArgs,
    id: &str,
    source_spec: &str,
    sha256: Option<&str>,
    allow_unverified: bool,
    allow_untrusted_host: bool,
    allow_unsigned: bool,
    insecure: bool,
) -> Result<()>

bamboo plugin update <id> <path-or-url> [--sha256] [--allow-unverified] [--allow-untrusted-host] [--allow-unsigned] [--insecure] — POST /api/v1/plugins/{id}/update (InstallDisposition::Upgrade). Same three-layer source-trust policy (plus the --insecure aggregate) as install (see the module docs).