How to implement custom validation in contact field

[bonjour_ken]

Hi there.

I would like to add required and validation to name field in contact page like email.
Is there any way to add simply validation by liquid code base (Not by JS)

I added code like below but it doesn't validate name field.

            <div class="grid__item medium-up--one-half">
              <label for="{{ formId }}-name">{{ 'contact.form.name' | t }} <span aria-hidden="true">*</span></label>
              <input
                type="text"
                id="{{ formId }}-name"
                name="contact[name]"
                value="{% if form.name %}{{ form.name }}{% elsif customer %}{{ customer.name }}{% endif %}"
                aria-required="true"
                {%- if form.errors contains 'body' -%}
                  class="input--error"
                  aria-invalid="true"
                  aria-describedby="{{ formId }}-name-error"
                {%- endif -%}
                >
              {%- if form.errors contains 'body' -%}
                <span id="{{ formId }}-name-error" class="input-error-message">
                  <span class="visually-hidden">{{ 'general.accessibility.error' | t }} </span>
                  {% include 'icon-error' %}
                  <span>{{ form.errors.translated_fields['name'] | capitalize }} {{ form.errors.messages['name'] }}.</span>
                </span>
              {%- endif -%}
            </div>

I checked developers document but I could not understand how to implement it.

Thank you for your help.