My code is saying a warning

What is wrong with my code I don't know what is wrong? but it says that Warning: Trying to access array offset on value of type null in C:\Users\Val\Downloads\XAMPP\htdocs\Login\firebase\station1.php on line 55-60

  1  <?php  include('includes/header.php'); ?>
  2  <?php session_start(); ?>
  3  
  4  
  5   <div class="container">
  6   	<div class="row">
  7   		<div class="col-md-12">
  8   			<?php
  9                 if (isset($_SESSION['status']) && $_SESSION['status'] != "")
 10                 {
 11                 	?>
 12  				<div class="alert alert-warning alert-dismissible fade show" role="alert">
 13    					Hey <?php echo $_SESSION['status']; ?>
 14    					<button type="button" class="btn-close" data-bs-dismiss="alert" aria-label="Close">	
 15    					</button>
 16  				</div>
 17                 	<?php
 18                      unset($_SESSION['status']);
 19                 } 
 20                  ?>
 21            </div>             			 			
 22  		<div class="col-md-12 mt-m5">
 23  			<div class="card">
 24  				<div class="card-body">
 25  					<div class="table-responsive">
 26  						<table class="table table-bordered">
 27  							<thead>
 28  								<tr>
 29  									<th>Title</th>
 30  									<th>Description</th>
 31  									<th>Location</th>
 32  									<th>Date_of_Incident</th>
 33  									<th>Time_of_Incident</th>
 34  									<th>Phone_No</th>
 35  									<th>Delete</th>
 36  
 37  									
 38  								</tr>
 39  							</thead>
 40  							<tbody>
 41  								<?php
 42  									include('includes/dbconfig.php');
 43  									$ref = "Station_1/";
 44  									$fetchdata = $database->getReference($ref)->getValue();
 45  									$i= 0;
 46  									if ($fetchdata > 0)
 47  									{
 48  
 49  
 50  									foreach ($fetchdata as $key => $row) 
 51  									{
 52  									 $i++;									
 53  								 ?>
 54  								<tr>
 55  									<td><?php echo $row['title']; ?></td>
 56  									<td><?php echo $row['description']; ?></td>
 57  									<td><?php echo $row['report_Location']; ?></td>
 58  									<td><?php echo $row['date_of_I  ncident']; ?></td>
 59  									<td><?php echo $row['time_of_Incident']; ?></td>
 60  									<td><?php echo $row['phone_Number']; ?></td>									
 61  									<td>
 62  										<form action="code.php" method="POST">
 63  											<input type="hidden" name="ref_toke_delete" value="<?php echo $key; ?>">
 64  											<button type="submit" name="delete_data" class="btn btn-danger">Delete</button>
 65  										</form>
 66  									</td>
 67  									
 68  								</tr>
 69  								<?php 
 70  									}
 71  									}									
 72  								?>
 73  								<a href="logout.php">Logout</a>	
 74  							</tbody>
 75  						</table>
 76  					</div>
 77  				</div>
 78  			</div>
 79  		</div>
 80  
 81  
 82  	</div>
 83  </div>