Cannot modify header information – headers already sent

Today, I have received a warning that WordPress cannot modify header information and headers are already sent, I do not know why showing this error message. I already contact my web host.

What should o do now?

WordPress Version 5.3.2

My Website: https://wcblogs.com

Thanks

Worth reading …

I would suggest checking wp-config.php and functions.php file.

Sorry for the late
and thanks for your update