So, I found the decision:
add_action( 'the_post', 'campaign_remove_nextpage', 99);
function campaign_remove_nextpage ( $post ) {
if (($_GET['utm_campaign']== 'Facebook' || $_GET['utm_campaign']== 'Twitter') && (false !== strpos( $post->post_content, '<!--nextpage-->' )) )
{
}
else {
$totalArticlesPages = substr_count($post->post_content, '<!--nextpage-->');
// Google: not paginated
// Direct: not paginated
// Camp: paginated
// Reset the global $pages:
$GLOBALS['pages'] = [ $post->post_content ];
// Reset the global $numpages:
$GLOBALS['numpages'] = 0;
// Enable multipage
$GLOBALS['multipage'] = false;
}};