I overrided these 2 methods and replaced: 'narration': self.note with 'narration': self.narration and order.narration but still it didn't work, do you have any idea why?

because sale order doesn't have narration field
narration field is in invoice

can you share your code so that i can help

Yes I want to update the narration field inside invoice and keep it the same in the sales order. I used the same functions but updated from note to narration. Do you have any solution regarding this issue?

HI MohammadShamass, Mohammad Chamass,

If you want that invoice will take the default terms and condition as you configured.
Not the sale order terms and conditions. Then you need to comment or remove the "narration" field in the below method.

Method : https://github.com/odoo/odoo/blob/15.0/addons/sale/models/sale_order.py#L604

By removing the "narration" from the above method, Invoice will take the default
terms and condition.

I commented the narration field from both methods but the problem still persists

I guess you have to check the final dictionary values at the end. It should not contains the "narration" key at all.
Please check the video i have shared in the updated answer.
Thanks

Thanks for the video! But the problem is still persisting, the place you changed the terms and conditions is the same place I changed it. I also changed it from the user-defaults section. I also removed the narration fields in both functions but till now I don't have any solution that helped me.

Then, you have to check wether your custom code has used that method or not.

This is the code, kindly check it:

from odoo import api, fields, models, _
from odoo.exceptions import AccessError, UserError
from odoo.tools import groupby

class AccountMoveInh(models.Model):
_inherit = 'account.move'

def _prepare_invoice(self):
"""
Prepare the dict of values to create the new invoice for a sales order. This method may be
overridden to implement custom invoice generation (making sure to call super() to establish
a clean extension chain).
"""
self.ensure_one()
journal = self.env['account.move'].with_context(default_move_type='out_invoice')._get_default_journal()
if not journal:
raise UserError(_('Please define an accounting sales journal for the company %s (%s).', self.company_id.name,
self.company_id.id))

invoice_vals = {
'ref': self.client_order_ref or '',
'move_type': 'out_invoice',
'currency_id': self.pricelist_id.currency_id.id,
'campaign_id': self.campaign_id.id,
'medium_id': self.medium_id.id,
'source_id': self.source_id.id,
'user_id': self.user_id.id,
'invoice_user_id': self.user_id.id,
'team_id': self.team_id.id,
'partner_id': self.partner_invoice_id.id,
'partner_shipping_id': self.partner_shipping_id.id,
'fiscal_position_id': (self.fiscal_position_id or self.fiscal_position_id.get_fiscal_position(
self.partner_invoice_id.id)).id,
'partner_bank_id': self.company_id.partner_id.bank_ids.filtered(
lambda bank: bank.company_id.id in (self.company_id.id, False))[:1].id,
'journal_id': journal.id, # company comes from the journal
'invoice_origin': self.name,
'invoice_payment_term_id': self.payment_term_id.id,
'payment_reference': self.reference,
'transaction_ids': [(6, 0, self.transaction_ids.ids)],
'invoice_line_ids': [],
'company_id': self.company_id.id,
}
invoice_vals=super(AccountMoveInh)._prepare_invoice(self)
return invoice_vals

def _prepare_invoice_values(self, order, name, amount, so_line):

invoice_vals = {
'ref': order.client_order_ref,
'move_type': 'out_invoice',
'invoice_origin': order.name,
'invoice_user_id': order.user_id.id,
'partner_id': order.partner_invoice_id.id,
'fiscal_position_id': (
order.fiscal_position_id or order.fiscal_position_id.get_fiscal_position(order.partner_id.id)).id,
'partner_shipping_id': order.partner_shipping_id.id,
'currency_id': order.pricelist_id.currency_id.id,
'payment_reference': order.reference,
'invoice_payment_term_id': order.payment_term_id.id,
'partner_bank_id': order.company_id.partner_id.bank_ids[:1].id,
'team_id': order.team_id.id,
'campaign_id': order.campaign_id.id,
'medium_id': order.medium_id.id,
'source_id': order.source_id.id,
'invoice_line_ids': [(0, 0, {
'name': name,
'price_unit': amount,
'quantity': 1.0,
'product_id': self.product_id.id,
'product_uom_id': so_line.product_uom.id,
'tax_ids': [(6, 0, so_line.tax_id.ids)],
'sale_line_ids': [(6, 0, [so_line.id])],
'analytic_tag_ids': [(6, 0, so_line.analytic_tag_ids.ids)],
'analytic_account_id': order.analytic_account_id.id if not so_line.display_type and order.analytic_account_id.id else False,
})],
}
invoice_vals=super(AccountMoveInh)._prepare_invoice_values(self, order, name, amount, so_line)
return invoice_vals