Deployer\Server\Configuration::setPassword PHP Method

    public function setPassword($password)
    {
        $this->password = $password;
        return $this;
    }

 /**
  * Set password for connection
  *
  * @param string|PasswordGetterInterface $password If you did not define password it will be asked on connection.
  *
  * @return Builder
  */
 public function password($password = null)
 {
     $password = $this->checkPassword($password);
     $this->config->setAuthenticationMethod(Configuration::AUTH_BY_PASSWORD);
     $this->config->setPassword($password);
     return $this;
 }