Display unit price for line item:

{% if line_item.unit_price_measurement %}
  {{ line_item.unit_price | money }}

  {% if line_item.unit_price_measurement.reference_value != 1 %}
    {{ line_item.unit_price_measurement.reference_value }}
  {% endif %}

  {{ line_item.unit_price_measurement.reference_unit }}
{% endif %}

Display unit price for variant:

{% if variant.unit_price_measurement %}
  {{ variant.unit_price | money }}

  {% if variant.unit_price_measurement.reference_value != 1 %}
    {{ variant.unit_price_measurement.reference_value }}
  {% endif %}

  {{ variant.unit_price_measurement.reference_unit }}
{% endif %}

Include this code in the relevant template or a section in the template.