Hello;

I have created a wizard which allows me to add button to user form :

class Wizard_client_ferm(models.TransientModel):


    _inherit = 'res.users'
    _name = 'affichage2.wizard_client'

    @api.model
    def create(self, values):
        return super(Wizard_client_ferm, self).create(values)


    #@api.model
    @api.multi
    def call_creation_ferm(self):


        ferme_form = self.env.ref('affichage2.creation_ferme_wizard', False)

        
        next_step2 = self.env['affichage2.wizard_ferm'].create({
            'farm_name': None,
            'farm_adress2': None,
            'wilaya': None,
            'list_packs': None,
            #'approved_by': next_step.id
            #'approved_by': self.next_step.id
        })


        return {
            'name': 'Creation de ferme',
            'type': 'ir.actions.act_window',
            'view_type': 'form',
            'view_mode': 'form',
            'res_model': 'affichage2.wizard_ferm',
            'view_id': ferme_form.id,
            #'res_id': next_step2.id,
            # 'res_id' : self.id,
            # 'context': {'current_id': self.id},
            # 'target': 'current',
            'nodestroy': True,
        }

Then i have defined my inherited wizard ( view ) :

<record id="wizard_user_form" model="ir.ui.view">
   <field name="name">affichage2.wizard_client.form</field>
   <field  name="model">affichage2.wizard_client</field>
   <!--field name="name">res.users.form</field>
   <field name="model">res.users</field-->
   <field name="type">form</field>
   <!--field name="inherit_id" ref="base.view_users_form"/-->
   <field name="arch" type="xml">
       <xpath expr="//field[@name='name']" position="after">
         <header>
           <button class="oe_highlight" type="object" name="call_creation_ferm" string="Suivant" />
           <button string="Cancel" class="oe_link" special="cancel" />
         </header>
       </xpath>
   </field>
</record>

<record model="ir.actions.act_window" id="wizard_client_form_action">
   <field name="name">Creation user</field>
   <field name="res_model">affichage2.wizard_client</field>
   <field name="view_type">form</field>
   <field name="view_mode">form,tree</field>
   <field name="view_id" ref="wizard_user_form"/>
</record>

The problem is when  i click in my new button in the user form view , i get this erreur :

AttributeError: type object 'res.users' has no attribute 'call_creation_ferm'