I want to create my custon and simple app  and I need to import phone_validation module. These module is correctly installed. The module is correctly installed, in fact in Database Structure -> Model is reported as        phone.validation.mixin. But when I try to install my custom module the system informs me that the phone_validation_mixin is not present in the
system. What am I doing wrong?

This is the code

mybooking_view.xml

<?xml version="1.0" encoding="UTF-8"?>
<odoo>
    <record model="ir.ui.view" id="mybooking_task">
            <field name="name">My booking Task Form</field>
            <field name="model">mybooking.task</field>
            <field name="inherit_id" ref="res.company.view.form.phone_validation" />
            <field name="priority" eval="15"/>
            <field name="arch" type="xml">
                <xpath expr="//field[@name='Name']" position="before">
                    <field  name="name"/>
                </xpath>
                <xpath expr="//field[@name='Surname']" position="before">
                    <field  name="surname"/>
                </xpath>
                <xpath expr="//field[@name='Data']" position="after">
                    <field  name="data"/>
                </xpath>
                <xpath expr="//field[@name='Treatment required']" position="after">
                    <field  name="treatment"/>
                </xpath>
                <xpath expr="//field[@name='Additional notes']" position="after">
                    <field  name="additionalNotes"/>
                </xpath>
            </field>
        </record>
</odoo>

<?xml version="1.0" encoding="UTF-8"?>
<odoo>
   <act_window id="action_mybooking_task"
      name="My booking validation"
      res_model="mybooking.task"
      view_mode="tree,form" />
   <menuitem id="menu_mybooking_task"
      name="Booking"
      action="action_mybooking_task" />
</odoo>

# coding: utf8
from odoo import models, fields


class MyBooking(models.Model):
    _name = 'mybooking.task'
    _description = 'my custom booking task'
    _inherit = 'phone.validation.mixin'
    name = fields.Char('Name', required=True)
    surname = fields.Char('Surname', required=True)
    data = fields.Datetime('Data', default=fields.Datetime.now())
    treatment = fields.Text('Treatment required')
    additionalNotes = fields.Text('Additional notes')