Hi,

The "Automate Sale And Purchase Orders" app for Odoo version 15 provides an option to automate the sale and purchase orders. One can automate the actions to confirm the quotation, create and validate invoices. Automatic actions are also available to confirm RFQ. A button can be added in the sale order and purchase order to print invoices and bills directly from the order form

Here is the link to the app:

https://apps.odoo.com/apps/modules/15.0/sale_purchase_automated/

Hope it helps

Check this below app

https://apps.odoo.com/apps/modules/15.0/sale_order_automation/