Caonical tag

Hello,
Some partners have asked to change the canonical tag to the source pemalink.
I tried the code bellow in functions.php but it crashes de site.
Is there any other way to do it?

add_action( 'wp_head', 'etruel_add_meta_tag', 0 );
function etruel_add_meta_tag() {
	global $post;
	$post_id = $post->ID;
	$post_permalink = get_permalink( $post_id, false );
	
	$wpe_campaignid = get_post_meta( $post_id, 'wpe_campaignid', true );
	$wpe_sourcepermalink = get_post_meta( $post_id, 'wpe_sourcepermalink', true );

	if (has_category('category-slug',$post->ID)){
		remove_action('wp_head', 'rel_canonical');
		echo '<link rel="canonical" href="'.$wpe_sourcepermalink.'" />';
	}
}