{% from "components/back-link/macro.njk" import govukBackLink %}

{% macro page_header(
  h1,
  back_link=None,
  size='large'
) %}

  {% if back_link %}
    {{ govukBackLink({ "href": back_link }) }}
  {% endif %}

  <h1 class="heading-{{ size }}" id="page-header">{{ h1 }}</h1>

{% endmacro %}

{% macro page_header(
  h1,
  size='large'
) %}

  <h1 class="heading-{{ size }}" id="page-header">{{ h1 }}</h1>

{% endmacro %}

Remove back_link parameter from page_header macro
Remove back_link parameter from page_header macro
