Display markers details in archive

I have mapsmarker working on wordpress and I want to display the markers in the map seperated from the map. For example all markers of all maps in an archive or simply sorted by category.

So I am looking for a way to use the mapsmarker API (get_marker) to display in a post the content of the marker object.

function my_marker_filter($content){
global $post;
if($post->post_title==’test_pagina’){
$db = new MMP\DB();
$marker = $db->get_marker(1);
//modify the incoming content
$content = $content . $marker[‘name’];
}
return $content;
}
add_filter( ‘the_content’, ‘my_marker_filter’ );

Where I am going wrong?

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