i have done as below, please advise:

1) created a custom field = x_confirm_sale_order_seq in sale.order

2) created a sequence (copied sale.order sequence & modified as required)

3) created an Automated Action (Trigger: On Update - Trigger Field: state)

Python Code:

if record.state == 'sale':

  if not record.x_confirm_sale_order_seq:

    seq = env['ir.sequence'].next_by_code('sale.order.confirm.seq')

    record.write({'x_confirm_sale_order_seq': seq})

when trying to Confirm in Quotations it is showing error:

ValueError: class 'ValueError': "invalid literal for int() with base 10: 'S000026'"

the sequence i have created as below:

Name: Sales Order Confirm Seq

Sequence Code: sale.order.confirm.seq

Sequence Size: 6

Steps: 1

Prefix: S

Next Number: 25

regards