PHP Call to a member function on a non-object

I get this error when trying to retrieve from the database.

Below is my code


<?php


require_once('Plant.php');


use backendless\Backendless;


include "vendor/backendless/autoload.php";
Backendless::initApp('6A4CE869-FBBA-968C-FF5B-6F5361917900', 'FC4982FB-CA6F-F21C-FF88-1DDBC5167600', 'v1');


$first_contact = Backendless::$Persistence->of('Plant')->findFirst();


$first_contact->getName();

<?php
class Plant {
 
    private $userId;
    private $tempLimit;
    private $name;
    private $lightLimit;
    private $lastWatered;
    private $humidityLimit;
    private $currentTemp;
    private $currentHumidity;
    private $currentLight;


    public function  __construct() {
        
    }
  
    public function getName() {
        return $thsi->name;
    }
 
    public function setName( $name ) {
        $this->name = $name;
    }


    public function getUserId() {
        return $thsi->userId;
    }
 
    public function setUserId( $userId ) {
        $this->userId = $userId;
    }


    public function gettempLimit() {
        return $thsi->tempLimit;
    }
 
    public function setTempLimit( $tempLimit ) {
        $this->tempLimit = $tempLimit;
    }


    public function getLightLimit() {
        return $thsi->lightLimit;
    }
 
    public function setLightLimit( $lightLimit ) {
        $this->lightLimit = $lightLimit;
    }


    public function getLastWatered() {
        return $thsi->lastWatered;
    }
 
    public function setLastWatered( $lastWatered ) {
        $this->lastWatered = $lastWatered;
    }


    public function getHumidityLimit() {
        return $thsi->humidityLimit;
    }
 
    public function setHumidityLimit( $humidityLimit ) {
        $this->humidityLimit = $humidityLimit;
    }


    public function getCurrentTemp() {
        return $thsi->currentTemp;
    }
 
    public function setCurrentTemp( $currentTemp ) {
        $this->currentTemp = $currentTemp;
    }




}

it may be because you get nothing here

$first_contact = Backendless::$Persistence->of('Plant')->findFirst();