zulip/static/templates/settings/custom_user_profile_field.hbs

<div class="user-name-section custom_user_field" name="{{ field.name }}" data-field-id="{{ field.id }}">
    <label for="{{ field.name }}" class="title">{{ field.name }}</label>
    {{#if is_long_text_field}}
    <textarea maxlength="500" class="custom_user_field_value">{{ field_value.value }}</textarea>
    {{else if is_choice_field}}
    <select class="custom_user_field_value">
        <option value=""></option>
        {{#each field_choices}}
        <option value="{{ this.value }}" {{#if this.selected}}selected{{/if}}>{{ this.text }}</option>
        {{/each}}
    </select>
    {{else if is_user_field }}
    <div class="pill-container person_picker">
        <div class="input" contenteditable="true"></div>
    </div>
    {{else if is_date_field }}
    <input class="custom_user_field_value datepicker" data-field-id="{{ field.id }}" type="text"
      value="{{ field_value.value }}" />
    <span class="remove_date"><i class="fa fa-close"></i></span>
    {{else}}
    <input class="custom_user_field_value" type="{{ field_type }}" value="{{ field_value.value }}" maxlength="50" />
    {{/if}}
    <div class="field_hint">{{ field.hint }}</div>
</div>