I cannot get the getPostTerms to work. It displays nothing. This one, however,  {{putPostTags(item.post_list.id)}} works as a charme, but I'd like to only get my filter-tags.

I cannot find any documentation about getPostTerms

My code, after your example

{% set terms = getPostTerms(item.post_list.id, "filter-taxonomy", true) %}
     
{% for term in terms %}

{{term.name}},

{% endfor %}