pma/templates/display/export/options_output_charset.twig

<li>
    <label for="select_charset" class="desc">
        {% trans 'Character set of the file:' %}
    </label>
    <select id="select_charset" name="charset" size="1">
        {% for charset in encodings %}
            <option value="{{ charset }}"
                {%- if (export_charset is empty and charset == 'utf-8')
                    or charset == export_charset %}
                    selected
                {%- endif %}>
                {{- charset -}}
            </option>
        {% endfor %}
    </select>
</li>