old_contents: from odoo import fields, models
  
  
  class ProductTemplate(models.Model):
      _inherit = "product.template"
      pos_notes = fields.Text("Notes for POS", translate=True)
  
  
  class PosProductNotes(models.Model):
      _name = "pos.product_notes"
      _description = "POS Product Notes"
  
      sequence = fields.Integer(string="Sequence")
      name = fields.Char(string="Note")
      pos_category_ids = fields.Many2many('pos.category', string='Point of Sale Categories',
                                          help='The note will be available for this group of POS categories.'
                                               'Leave the field empty so that the note is available for all POS categories.')
  
new_contents: from odoo import fields, models
  
  
  class ProductTemplate(models.Model):
      _inherit = "product.template"
      pos_notes = fields.Text("Notes for POS", translate=True)
  
  
  class PosProductNotes(models.Model):
      _name = "pos.product_notes"
      _description = "POS Product Notes"
  
      sequence = fields.Integer(string="Sequence")
      name = fields.Char(string="Note")
      pos_category_ids = fields.Many2many('pos.category', string='Point of Sale Categories',
                                          help='The note will be available for this group of POS categories. '
                                               'Leave the field empty so that the note is available for all POS categories.')
  
subject: Update pos_order_note/models/models.py