It can also be done with an Automated Action.  

You have to create new Sequence numbering and then some simple Python code in the Automated Action.

Sequence Numbering:  

The Python code in the Automated Action will be something like this:

for record in records:
  ref = env['ir.sequence'].next_by_code('crm.lead.sequence')
  record['name'] = ref

This example provides more details: https://odootricks.tips/set-sequence-numbers-for-sales-orders/

Hi,

Please utilise the provided code below to update the opportunity name.

from odoo import models, fields, api

import random

from datetime import datetime

class CRMOpportunity(models.Model):

    _inherit = 'crm.lead'

    name = fields.Char(string="Opportunity Name", compute="_compute_custom_opportunity_name", store=True)

    @api.depends('date_deadline')

    def _compute_custom_opportunity_name(self):

        for opportunity in self:

            # Format date as "DDMMYYYY"

            formatted_date = datetime.strptime(opportunity.date_deadline, '%Y-%m-%d').strftime('%d%m%Y')

            # Generate random letters/numbers (you may adjust this based on your requirements)

            random_part = ''.join(random.choices('ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789', k=6))

            # Combine the elements

            opportunity.name = f'REN/{formatted_date}/{random_part}'

Regards

Hello Galien, 

For this you need to generate the sequence. you can follow this community answer : https://www.odoo.com/forum/help-1/create-a-sequence-number-internal-reference-for-project-task-110287

Thanks