Thank you…I have found solution too. If someone wants use Google Content Experiments plugin.
Within your theme, locate the file where the <head> tag is inserted (probably something like header.php)
Place <?php do_action( ‘wpe_gce_head’ ); ?> right after <head>
Save the file
I tried code block but it is not correct. Google Analitics send me message that GA core tracking code is before GA experiment code. GA exp. code have to be before GA core code in Head section immediately after <head>. Some suggestion?
I go try it
I meant addition tracking code for custom pages. It can be done by Google Tag Manager too. But thanks for answer.
thank you