"DataConnection": {
    "Servidor": "localhost",
    "Porta": "5432",
    "Usuario": "postgres",
    "Senha": "334522",
    "NomeBancoDados": "Retaguarda",
    "DiretorioComando": "C:\Program Files\PostgreSQL\11\bin",
    "DiretorioBackup": "C:\Users\JALBER\Downloads\",
    "NomeArquivo": "Backup_Retaguarda_"
  }

public void CreateBackup(BackupRestore backupRestore)
{
    Environment.SetEnvironmentVariable("PGPASSWORD", backupRestore.Senha);

    string backupFile = backupRestore.DiretorioBackup + backupRestore.NomeArquivo + DateTime.Now.ToString("yyyy") + "_" + DateTime.Now.ToString("MM") + "_" + DateTime.Now.ToString("dd") + ".backup";
    string BackupString = "-ibv -Z3 -f "" + backupFile + "" " +
     "-Fc -h " + backupRestore.Servidor + " -U " + backupRestore.Usuario + " -p " + backupRestore.Porta + " " + backupRestore.NomeBancoDados;

    Process proc = new System.Diagnostics.Process();
    proc.StartInfo.FileName = backupRestore.DiretorioComando + "\pg_dump.exe";
    proc.StartInfo.Arguments = BackupString;

    proc.Start();
    proc.WaitForExit();
    proc.Close();
}