odoo-pos-addons/pos_restaurant_table_booking/views/res_config_settings.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>

  <record id="res_config_settings_form" model="ir.ui.view">
    <field name="name">Booking res.config.settings form</field>
    <field name="model">res.config.settings</field>
    <field name="inherit_id" ref="point_of_sale.res_config_settings_view_form"/>
    <field name="arch" type="xml">
      <xpath expr="//div[@data-key='point_of_sale']/h2[1]" position="before">
        <h2>Bookings</h2>
        <div class="row mt16 o_settings_container" name="bookings_setting_container">
          <div class="col-12 col-lg-6 o_setting_box" id="default_duration_setting" title="This duration is applied to any new booking created in the point of sale.">
            <div class="o_setting_right_pane">
              <div>
                <label for="default_duration"/>
                <!-- <div class="text-muted">
                Default sales tax for products
              </div> -->
              <div class="content-group mt16">
                <field name="default_duration" colspan="4" nolabel="1" widget="float_time" class="oe_inline"/>
              </div>
            </div>
          </div>
        </div>
      </div>
    </xpath>
  </field>
</record>

</odoo>