Image file path cannot upload to MySQL database using PHP

one text

I'm using PHP, I try to upload the image file path in MySQL Database, but the path cannot upload and it always shows as NULL my code are provide below.

                if(isset($_FILES['img']) && $_FILES['img']['tmp_name'] != ''){
                    $fname = 'uploads/avatar-'.($id).'.png';
                    $dir_path =base_app. $fname;
                    $upload = $_FILES['img']['tmp_name'];
                    $type = mime_content_type($upload);
                    $allowed = array('image/png','image/jpeg');
                    if(!in_array($type,$allowed)){
                        $resp['msg']=" But Image failed to upload due to invalid file type.";
                    }else{
                        $new_height = 200; 
                        $new_width = 200; 
                
                        list($width, $height) = getimagesize($upload);
                        $t_image = imagecreatetruecolor($new_width, $new_height);
                        imagealphablending( $t_image, false );
                        imagesavealpha( $t_image, true );
                        $gdImg = ($type == 'image/png')? imagecreatefrompng($upload) : imagecreatefromjpeg($upload);
                        imagecopyresampled($t_image, $gdImg, 0, 0, 0, 0, $new_width, $new_height, $width, $height);
                        if($gdImg){
                                if(is_file($dir_path))
                                unlink($dir_path);
                                $uploaded_img = imagepng($t_image,$dir_path);
                                imagedestroy($gdImg);
                                imagedestroy($t_image);
                                if(isset($uploaded_img) && $uploaded_img == true){
                                    $qry = $this->conn->query("UPDATE users set avatar = concat('{$fname}','?v=',unix_timestamp(CURRENT_TIMESTAMP)) where id = '$id' ");
                                }
                        }else{
                        $resp['msg']=" But Image failed to upload due to unkown reason.";
                        }
                    }
                    
                }

I want to upload the image file path and display the image