How can I split the body field to insert content between the first and the second paragraph?
I resolved my issue, using solution below
    {% set Paragraphs = node.body.value|split('&lt;/p&gt;') %}
  {% set paragraphHalf = (Paragraphs|length / 2)|round %}
  
  {% if paragraphHalf %}
    {% for paragraph in Paragraphs %}
      {% if paragraphHalf == 1 or loop.index % paragraphHalf == 1 -%}
        
      {% endif %}
      {{ paragraph|raw }}

      {% if loop.last or loop.index % paragraphHalf == 0 -%}
      {{ insert item }}
      {% endif %}

    {% endfor %}

  {% endif %}