Warning: Cannot modify header information - headers already sent by (output started at C:\xampp\htdocs\qrcode\html\user\header.php:106) in C:\xampp\htdocs\qrcode\html\user\phpqrcode\qrimage.php on line 35 code example

Example: Warning: Cannot modify header information - headers already sent by (output started at C:\xampp\htdocs\heermatka\myprofile.php:48) in C:\xampp\htdocs\heermatka\myprofile.php on line 144

ob_start();
Please paste top on the page.