Merge Image save to mysql database without clicking anything

Can anyone help me about my problem?
I have successfully merge a image but i dont know how to insert it into DB

the code is something like this
 <?php
      $logo = "SecurityBank.png";
      $white_image = "image_size.png";
      $targetfile = "Phobo_New_Image.png";

      $Whitebackground = imagecreatefrompng($white_image);
      $whitebgW = imagesx($Whitebackground)-300;
      $whitebgH = imagesy($Whitebackground);
                        
      $partnerlogo = imagecreatefrompng($logo);
      $partnerlogoW = imagesx($partnerlogo);
      $partnerlogoH = imagesy($partnerlogo);
                  
      $photoFrame = imagecreatetruecolor($whitebgW,$whitebgH);
        $destlogo_x = $whitebgW - $partnerlogoW;
      $destlogo_y = $whitebgH - $partnerlogoH;
                  
      imagecopyresampled($photoFrame, $Whitebackground, 0, 0, 0, 0, $whitebgW, $whitebgH,$whitebgW, $whitebgH);
      imagecopy($photoFrame, $partnerlogo, $destlogo_x-300, $destlogo_y-400, 0, 0, $partnerlogoW, $partnerlogoH);
      imagepng($photoFrame, $targetfile);
?>
<center><img src="<?php echo $targetfile ?>" width="700px" name="target" id="target" height="400px"></center>'

<!-----THE NEW MERGED IMAGE IS BEEN SHOWED
name="target" id="target"
--->

I want to insert it into datbase my setTimeout or anything that the file $target is save into to the database as blob or longtext.