Odoo 16

When placing an order on the POS, the work flow is

1. Add items to cart

2. Press Payment

3. Enter payment method / amount and Validate

The next page shows email or print receipt at the bottom NEW ORDER

I need to replace the NEW ORDER with Complete Order and log the cashier out every time.

Reading through the forum someone has answered

Try adding this.trigger('user_logout'); in the function for validate or next order

Will this work and which file and where is the file located for this edit?

Or does any one have a better solutions, there are third party apps for this but not for version 16

Willing to pay for this, needed urgently thanks in advance