1. Go to Sales ‣ Configuration ‣ Quotations Templates and click New.
2. After having named the template, choose default values for the following fields:
Quotation expires after: choose the number of days for which the quotation is valid.
Online confirmation: after sending the quotation by email, it is possible to ask the customer to confirm it online on their customer portal:
by providing a Signature,
by making a Payment,
or both.
Confirmation Mail: select an email template to automatically send an email to the customer upon confirming the quotation.
On the Lines tab, add the default products and their quantity. Add optional products in the Optional Products tab.
Finally, add any specific sales terms and conditions on the Terms & Conditions tab.
You can search more information in https://www.odoo.com/documentation
https://hauntthehouse.io