change customer to client and make it require

cor_custom/views/sale_views.xml

@@ -6,15 +6,20 @@
         <field name="model">sale.order</field>
         <field name="inherit_id" ref="sale.view_order_form"/>
         <field name="arch" type="xml">
-            <page name="customer_signature" position="attributes">
-                <attribute name='invisible'>1</attribute>
-            </page>
+            <xpath expr="//field[@name='partner_id']" position="replace">
+                <field name="partner_id" widget="res_partner_many2one" string="Client" required="1"
+                       context="{'res_partner_search_mode': 'customer', 'show_address': 1, 'show_vat': True}"
+                       options='{"always_reload": True}'/>
+            </xpath>
             <xpath expr="//field[@name='require_signature']" position="replace">
                 <field name="require_signature" invisible="1"/>
             </xpath>
             <xpath expr="//field[@name='require_payment']" position="replace">
                 <field name="require_payment" invisible="1"/>
             </xpath>
+            <page name="customer_signature" position="attributes">
+                <attribute name='invisible'>1</attribute>
+            </page>
         </field>
     </record>
 </odoo>