header location and warning headers already sent

Hello, I’m trying to make an authentification code which redirect user to his own profile, but the problem is that I can’t use header location of php and it always shows me this message:
Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-includes/general-template.php:1076) in /var/www/html/wp-content/plugins/insert-php-code-snippet/widget.php(64) : eval()’d code on line 30

Please any help for this problem? How can I redirect my client to his own page?

• This topic was modified 6 years, 3 months ago by yosraa.