{% set hosts = ['1', '2', '3'] %}
{% set addrs = [] %}
{% for addr in addrs %}
    {% do addrs.append(addr ~ "4161") %}
{% endfor %}

debug:
    test.show_notification:
        - name: Debug Information
        - text: |
            abc
            {{ addrs | join(' ' ) }}
            cbd

Output:

     Comment: abc

              cbd