Magento 2 redirection not working?

Question

I implemented redirection for users when some condition become true. My code

<?php

namespace send\sms\Observer;

use Magento\Framework\Registry;
use Magento\Framework\Event\ObserverInterface;
use Magento\Framework\Exception\LocalizedException;
use Magento\Framework\Message\ManagerInterface;


class check implements ObserverInterface
{

    protected $redirect;
    protected $_customerSession;
    protected $_objectManager;
    protected $_urlInterface;


    public function __construct(
        \Magento\Customer\Model\Session $customerSession,
        \Magento\Framework\App\Response\RedirectInterface $redirect,
        \Magento\Framework\ObjectManagerInterface $objectManager,
        \Magento\Framework\UrlInterface $urlInterface
    ) {

        $this->_customerSession = $customerSession;
        $this->redirect = $redirect;
        $this->_objectManager = $objectManager;
        $this->_urlInterface = $urlInterface;
    }

    public function execute(\Magento\Framework\Event\Observer $observer)
    {
        $actionName = $observer->getEvent()->getRequest()->getFullActionName();
        $controller = $observer->getControllerAction();

        $obm = \Magento\Framework\App\ObjectManager::getInstance();
    /** @var \Magento\Framework\App\Http\Context $context */
    $context = $obm->get('Magento\Framework\App\Http\Context');
    /** @var bool $isLoggedIn */
    $isLoggedIn = $context->getValue(\Magento\Customer\Model\Context::CONTEXT_AUTH);
    if($isLoggedIn){ 
      $om = \Magento\Framework\App\ObjectManager::getInstance();
           $customerSession = $om->create('Magento\Customer\Model\Session');
           $suser_id = $customerSession->getCustomer()->getId();
    $this->_resources = \Magento\Framework\App\ObjectManager::getInstance()->get('Magento\Framework\App\ResourceConnection');   
    $connection= $this->_resources->getConnection();
    $tableName = $this->_resources->getTableName('otpp');
    $sql = "SELECT verified FROM otpp WHERE `entity_id`='$suser_id'";
    $result = $connection->fetchall($sql);
    @$otparray = $result['0']; 
    $verified = $otparray['verified'];



        if($verified == 0) {
            $url = $this->_urlInterface->getUrl('otp/index/index'); // give here your controller/action
        // below code redirects to cart controller
        $observer->getControllerAction()
                    ->getResponse()
                    ->setRedirect($url);
        }

    }
    }

}

Answer 1

Try this

  <?php

    namespace send\sms\Observer;

    use Magento\Customer\Model\Session;
    use Magento\Framework\App\ObjectManager;
    use Magento\Framework\App\Response\RedirectInterface;
    use Magento\Framework\Event\Observer;
    use Magento\Framework\Event\ObserverInterface;
    use Magento\Framework\ObjectManagerInterface;
    use Magento\Framework\UrlInterface;


    class Check implements ObserverInterface
    {

        protected $redirect;
        protected $_customerSession;
        protected $_objectManager;
        protected $_urlInterface;


        public function __construct(
            Session $customerSession,
            RedirectInterface $redirect,
            ObjectManagerInterface $objectManager,
            UrlInterface $urlInterface
        ) {

            $this->_customerSession = $customerSession;
            $this->redirect = $redirect;
            $this->_objectManager = $objectManager;
            $this->_urlInterface = $urlInterface;
        }

        public function execute(Observer $observer)
        {
            if ($this->_customerSession->isLoggedIn()) {
                $suser_id = $this->_customerSession->getCustomer()->getId();
                $resources = ObjectManager::getInstance()->get('Magento\Framework\App\ResourceConnection');
                $connection = $resources->getConnection();
                $tableName = $resources->getTableName('otpp');
                $sql = "SELECT verified FROM $tableName WHERE `entity_id`='$suser_id'";
                $result = $connection->fetchall($sql);
                if(count($result) > 0) {
                    $verified = $result['0']['verified'];
                    if ($verified == 0) {
                        $url = $this->_urlInterface->getUrl('otp/index/index'); // give here your controller/action
                        // below code redirects to cart controller
                        $observer->getControllerAction()
                            ->getResponse()
                            ->setRedirect($url);
                    }
                }
            }
        }

    }

Answer 2

Kindly use following ;

<?php
namespace [Vendor]\[modulename]\Observer;
use \Magento\Framework\Event\Observer;
use \Magento\Framework\Event\ObserverInterface;
class [YourClass] implements ObserverInterface {
    protected $_responseFactory;
    protected $_redirect;
    protected $_url;
    public function __construct(
        ......
        \Magento\Framework\App\ResponseFactory $responseFactory,
        \Magento\Framework\UrlInterface $url,
        \Magento\Framework\App\Response\Http $redirect,
        ......
    ) {
        $this->_responseFactory = $responseFactory;
        $this->_url = $url;
        $this->_redirect = $redirect;

    }
    public function execute(Observer $observer) {

             $CustomRedirectionUrl = $this->_url->getUrl('otp/index/index');
             $this->_redirect->setRedirect($CustomRedirectionUrl);

    }
}

Answer 3

$url = $this->getResponse()->setRedirect('otp/index/index');

or use this also

$resultRedirect = $this->resultFactory->create(ResultFactory::TYPE_REDIRECT); return $resultRedirect->setUrl('otp/index/index'');